In the campaign I'm currently running and playing in, due to time constraint or just trying to push thematic elements, we end up basically doing 1 fight per long rest; So really nothing crazy (and honestly this is what I've seen as most common in all my games). I think this leads to most players blowing through all their resources and going Nova for one fight, so then after that fight they're basically all tapped out, which makes any following conflict really interesting as all players are out of most of their resources. I do think the positive side of just having one big fight is that it lends your players to being more free with their resources, using spell slots, lucky points, or inspiration for out of combat checks rather than hoarding them expecting several fights. I think both takes have their merits, but I haven't given the dungeon crawly type campaign enough of a shot to really opine on it in an educated fashion.