I use as few long rests as possible, which is in part because I play mostly martial characters. I generally tend to avoid using many leveled spells and even my martial characters tend to use their powers sparingly due to my dislike of their flashy Vfx. Also, I generally don't use long rest while I still have short rests available.
I've also never been to the Underdark (aside from the Selunite outpost once in patch 1), due to the fact that I have strong dislike for the Underdark in basically every D&D game... be it video game or PnP. Therefore it's hard to say what effect it would have on my resting behaviour.
