Risks of letting the party take their time?

[Protato]

I was wondering what risks could be in place for when the party takes their sweet time to get around to doing something. For example, let's say the party has to get somewhere which takes two weeks, and then they teleport back home, but they have the option to spend another week plus some gold at their destination to learn a Feat, gain more knowledge, or otherwise earn some sort of boon. While the money cost is obviously a disincentive, how could time be used to make it more of a risk-reward proposition?

[nickl_2000]

Options that I can think of quickly.

-The chance of failure at the goal since they took so long
-Maybe they spend so much time the weather turns on them requiring them to travel through snow and gaining exhaustion
-The enemies have had more time to set up traps (leave trap plans sitting around so they know that the traps are there because of the time)
-The enemies receive reinforcements
-The item that they tried to find/ person they tried to find has been moved
-They get a sending that there is goblin activity around their home and some of it gets destroyed if they wait to long

[FelineArchmage]

Options that I can think of quickly.

-The chance of failure at the goal since they took so long
-Maybe they spend so much time the weather turns on them requiring them to travel through snow and gaining exhaustion
-The enemies have had more time to set up traps (leave trap plans sitting around so they know that the traps are there because of the time)
-The enemies receive reinforcements
-The item that they tried to find/ person they tried to find has been moved
-They get a sending that there is goblin activity around their home and some of it gets destroyed if they wait to long

This.

Just because your players are taking their sweet old time and chillin' around, doesn't mean the antagonist/whatever the party is going against is doing the same thing. If you have a villain in your story, they still have their own plans and will move forward with them (and will probably have an easier time of it since the players aren't in their way).

[Vogie]

Introduce a 3rd party - not really an antagonist, but an individual or group that is also interested in certain places or items for different reasons. This could include:

Tomb Raiders
Body Snatchers
Thieves
Other Adventuring parties trying to make a name for themselves
Dread Pirates
Inigo Montoya
NPCs who would have joined the PCs' party briefly, had they gotten there in time

[Protato]

I'll probably be having the villain (or villain) be making some sort of move while the party makes preparations to make theirs. My villain idea right now is a Lich that wishes to acquire "true" immortality in their old body rather than being stuck as an undead. There's a tree in another realm that bears fruit that can grant immortality (and possibly something close to godhood) but for whatever reason he can't enter the realm and take it himself, so he needs to capture a party member to do it for them, and to kill the rest. He can sense the "magic signature", as it were, of this fruit and since the party bottled its juice, the Lich decided the party might now how to get there. The party doesn't know any of this yet though, but I plan to have them go to a library to learn it, with a session happening on the road. My main thoughts are, since they'd be on the road, the villain would probably try to amass forces first thing, and to assemble a sort of "elite team" of powerful minions. While simple, I was thinking the first time the party encounters on of these elites, if the party waited, they have a larger team of more powerful minions (by at least one CR) than if they had simply completed the "main" goal.

[Mellack]

I think it really depends on what the adventure is about. A bandit chief might be able to recruit more men to his group. A kidnapping victim might have already been ransomed/killed. An evil wizard might now already be a lich. Or if it is a dungeon nobody else knows about or can get to, nothing at all might change.