If i do nothing to help them, will they still find the hotel in the end? and vice versa, if i actually try, will they find it faster?

well, no to both things. you will find the hotel regardless, hinterlands 3 has no impact in that. however, there are at least 3 other things you should do for the best outcome. i recommend you try and investigate to see if you can figure out the mysteries involved in that chapter.

Maybe the real hotel was the friends we made along the way.

Jokes aside, P and Storm will find the hotel regardless of what you do, but accomplishing certain things will have long-lasting consequences later in the game.