How to survive Plane of Ice?

[SangoProduction]

Long story short: Portal guy put a portal inside of a portal to hell, which shunted us to the astral plane, and then he put another portal inside that portal. The demon's dead.
We're unconscious in a cavern of ice on the plane of ice.

So... We at least didn't end up crushed between two slabs of ice, which is the good news.

Aside from trying to look for a portal back to the material realm, what do we do about this? What are the things to look out for and prepare against?
Not as though the characters would know, but I never even heard of the plane of ice until this session.
I imagine Cold Resistance and protection from elements would be useful... But that's about it.

[Thunder999]

Depending on exactly which version you're using there's a decent chance the cold there will pierce cold immunity, freeze fires and generally be extremely hard to protect from.

The plane of water should be at the bottom of the plane and the plane of air at the top. If you can make it to either you can probably convince a Djinni or Marid to plane shift you out in return for some kind of favour or payment.

The top is a vast sheet of ice, there's lots of ice caverns below and eventually they give way to icebergs floating on water.

Oh and expect avalanches, random holes and shifting ice.

There should be portals to other planes, not that you're necessarily anywhere near one.

Can't portal guy just repeat his trick until you get lucky enough to land somewhere better?

[Quentinas]

I hope you have attune form or a similar spell, as that would probably avoid the subdual damage that you will take every 10 minutes if you stay too long, Being able to fly could be quite useful so you would avoid the shifting ice, maybe the avalanches and you would not have any problem at balancing for the ice. As you said protection from energy, or directly immunity from energy would be useful maybe endure element instead of attune form but i'm not sure if only endure element would help. The best option would be defending yourself as portal guy/cleric of the group are ready to shift you of plane again so one day... so good luck if you don't have any spell ready to protect you from the hazard and the subdual damage
In my campaign my plane of ice is the elemental plane of cold of the manual of the planes so i said that rules. Not that my players should go here... but after they put a bag of holding inside an handy haversack i don't expect anything

[Fizban]

The most important questions of what levels and classes (spell lists) the party has, are missing. "Portal guy" sounds like quite a few levels, but worrying about cold and how to get back to the material plane are not high level concerns.

The Elemental Plane of Cold given in Manual of the Planes is only 0 degrees, easily within basic Endure Elements, and doable with sufficient cold weather clothing if you already have it. At least, until you account for the extra -1 band for Wind Chill, and if 0 degrees is the daytime it could have another -1 for Nightfall. Which would bring the total to Extreme Cold, still negated by simple Endure Elements as long as you don't touch any metal. If you're at Extreme Cold and don't have Endure Elements, the most you can achieve is partial protection, requiring both a cold weather outfit and extra furs, and you'll still have to roll every hour, unless you're taking shelter.

On the other hand, if the DM is thinking Ice like big ice damage per round, and does the same as Cania by flipping the 3d10 per round for Fire Dominant planes into 3d10 cold per round, well in that case you'd probably know and/or be dead by now (unless you had the exact spells required already prepared, Avoid Planar Effects followed by Attune Form, but you don't). Speaking of which- are you in a cavern like a big interconnected network of tunnels and pockets, or like a tiny sealed air pocket you'd find on the Plane of Earth where you're about to suffocate? If you're in what is considered a safe zone but the rest of the plane deals lol damage, then your Cleric or Druid can solve it with a couple 3rd level spells, but if you're about to suffocate you're screwed unless you teleport out or already have the right items.

The Elemental Plane of Cold is given as as endless expanse of water covered by an endless glacier/iceburg, at 0 degrees, with a day/night cycle and a 50% chance of extreme weather every day, and interfering with fire magic while boosting cold magic. It says there are normal material plane animals that can be hunted, but I don't see how when there should be no vegetation whatsoever. Furthermore, if the water is covered by an endless glacier and is sub-freezing, the amount of life down there is questionable (no light means no plankton means no food chain).

I would expect Ice Paraelementals, which are basically fire but slower with a Chill Metal aura (presumably no-save?), as well as White Dragons, Frost Giants, maybe Ice Devils, and anything from Frostburn. Ice elementals don't actually have an "ice-glide" ability, but some stuff in frostburn does, and I would not be surprised if whatever they use for an ice elemental ice-glides even if it wasn't printed with the ability. The Cold Element creature template could be applied to anything, and while it does not provide ice-glide, it does give the White Dragon's icewalking, so anything that looks like it's been templated to match the plane can walk on walls. Similarly, I would not be surprised if you ran into Coldfire and Frostburn damage, the former being a dangerous substance, and the latter being un-healable until you've entered a warm area or use the right spells. Basically just go read all the hazards and Cleric spells in Frostburn.

Fire spells will be less reliable due to the planar interference, and cold spells powered up. Protection from Energy will be burned out quite quickly: better to rely on Energy Immunity, or Anticold Sphere for combat, the latter of which gives a whole area immunity and also blocks natural attacks from [cold] creatures, it's kinda bonkers- but unless you have Druid, you can't pull it out of nowhere. If you're there long term, note that Piercing Cold explicitly does not allow damage against the [cold] subtype, so seeking that out could be useful, but also note that SpC mucked with the spells from Frostburn and Sandstorm for gaining the subtypes.

Ground-up worldbuilding indicates that there should be a harsh dichotomy between things that have at-will cold attacks, and those that are actually susceptible to them. Monsters are designed for fighting PCs and expect their damage to be a threat, but in a world where everything is immune to cold, the true winners are those that don't actually rely on cold damage- giants are usually up there.

Frostburn provides a cold genie, so you could be looking at a "City of Brass" situation where there's actually a great big city where you can find a portal or hire a ride home. But, genies like enslaving people (though it's not mentioned specifically in the Qorrahi entry), so you could also be about to wake up in chains.

[SangoProduction]

Oh right, party composition.
Portal Guy is a kineticist archetype that focuses on portals. He lacks the ability to control which plane he sends us to with his antics.
Our Lizardfolk is some sort of dancing fighter.
We've got a Hexblade type duelst.
And then me, who is a lichling, with stand out powers being ability to animate dead for a minute at a time and aligned auras that inhibit evil. Oh, and to be damaged by positive energy, as payment for getting to dump Con.

We just turned level 7 and mythic 2.