This is purely hypothetical, just for fun. In this scenario, you don’t get to know who the GM is in advance, but they do have to run it as written. The players can leave whenever they like, but the GM has to stay until either all players leave or the players beat the dungeon.
Mention things in other rooms of the dungeon without giving page numbers. In one room, note that a specific trap lets out a subsonic noise that can be heard by a specific type of creature, but don’t say where those creatures actually are in the dungeon. Have a magical artefact that, once touched, can be immediately sensed by another type of creature. Things like that. In at least one instance, refer to something that isn’t actually anywhere in the dungeon.