I don't roleplay time-wise quite the way you are suggesting, but I certainly take an approach where I treat spells (and abilities, etc) as a scarce resource and only use just as many and as powerful a spell/ability/etc as I HAVE to in order to beat a certain opponent or achieve a certain task. Only when I'm seriously depleted do I hole up somewhere to rest.
I personally think the concept of "go into the next room and kill all the baddies with all my highest-level spells/abilities/etc, then rest, then go into the next room and kill all the baddies with all my highest-level spells/abilities/etc, then rest, etc" as being a very poor, boring way to play.
I would love to see a CRPG that prevented you from resting within a certain time period of resting previously!
This would discourage a lot of cheese tactics (such as endless setting of traps) as well.
And, surprisingly, no - I don't find myself reloading a lot, so I think the game is well balanced enough to allow a careful and resourceful party to last quite a while between rests. (The plot is also often see-through enough to know when you're about to meet a tough opponent!)