Divination vs Commune: Pros & Cons of each?

[Cygnia]

So, we're in a high-level (lvl15) campaign where we're cleaning up the mess of a previous campaign of other characters (one in which I was not involved in as a player). Basically, we need to sneak into the Evil Empire and steal/destroy the MacGuffin all the while avoiding baddies. Time is of the essence, of course and we're a pretty far distance away on foot (no mounts and airships are too blatant).

I'm the token divine caster (tempest cleric). For now, the plan is attempting Divine Intervention to beseech my deity to get us as safe yet close to the MacGuffin as possible, but that's still a tall order. Still, the GM has sworn he won't monkey-paw DI or any type of divining magic.

So, since we're at the "halfway" part of the journey and at least one of our party members has evil (wyvern-riding) enemies after him (he blocked a scrying attempt made on him), I'm considering either casting Divination or Commune to get a nudge towards which way to go. I'm also trying to poke my party members for advice/what question(s) to ask, but they're dragging their feet on that end.

Which spell would be the more useful choice to cast here?

[Darth Credence]

I think this depends quite a bit on the DM, but I'll give you how I DM the two spells to see if it helps.

Commune, you get three questions, but they have to be answerable by yes/no. If someone casts it, I remind them of that. Then if they ask a non yes/no question, I remind them again, and attempt to rearrange the question with them. If question 2 is also not the right form, I let them know, and let them reformulate themselves. If question 3 is also not yes/no, then they wasted that question.
The biggest problem with commune, though, is that you have to have a pretty good idea of what you are looking to do for it to be useful. You can't ask, "which way should we go?" If you have no idea, you could pick a direction and ask if you should go that way, and get three shots at it, but it's easy to end up with "no" three times. As a 5th level spell, that's a decent amount of power to use, even at 5th level, so I'd be wary of using it in general, but definitely if I didn't have things narrowed down substantially already. In your case, I would only do commune if I had a few plans I wanted to narrow down to which one to pick.

Divination is only 4th by comparison, and gives a cryptic answer, but at least more than yes/no. However, the "event" and the time limit make it hard to run, and DMs often have vastly different interpretations. I, personally, have a tarot deck that I stack with what I want when they cast divination, and it is on them to figure out what it means, but that's fun for us, and may not be for others. Depends on the DM and the group.
If the DM enforces the "7 days" part, and you are more than 7 days away from the MacGuffin, then nothing asked about it in particular is going to get an answer. If the DM leans hard into crytpic, you may get an answer that seems really obvious once the game is over and you know what they meant, but until then is basically worthless. However, some DMs will just straight up answer the question - "Which way should we go to find the MacGuffin?" "You must head to the north, skirting the forest of pain and crossing the lake of tears in a rowboat." In that case, Divination is the clear winner.

So, know your DM. I think divination has the most promise, but could be completely worthless for what you are attempting.

[NecessaryWeevil]

If you need to choose between a limited number of discrete choices (left or right? By land or by sea?), then Commune. Otherwise, Divination. (Edit: ninjaed!)