| One alternative, especially given the shallowness of the XP curve, would be to have each floor of the dungeon equate to about 2-3 levels worth of xp. So when the party enters the dungeon at level 1, the first floor contains 25-30 encounters some of which at level 1, some at 2 and some at 3, but not necessarily in order. Since XP is fixed, by the time they get through the level, they'll be 3rd-4th level, and ready to take on the 2nd floor, which has encounters of 4th-6th. Just because tradition has one floor per level doesn't mean it has to stay that way.
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All we want to do is eat your brains
We’re not unreasonable; I mean, no one’s gonna eat your eyes
All we want to do is eat your brains
We’re at an impasse here; maybe we should compromise:
If you open up the doors
We’ll all come inside and eat your brains | 
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