Tony Vargas
Legend
My impulse would be to run it like in the classic game. Anyone can enter or leave it (except the caster, if he leaves it collapses), it's opaque from the outside, and is a nice, magical, tent that protects the party from the elements.I agree that the metagame intent seems clear. Which is why I personally find the bulette, piles of rocks, etc "countermeasures" pretty irrelevant. Either one embraces the metagame intent and uses the spell as you describe, or else one rejects the metagame intent and hence doesn't include the spell in one's game (removing it, gentlemen's agreement to ignore it, whatever).
Besides, doesn't Rope Trick, a level earlier, give you uninterruptible-rest/5MWD capability, too?