Don't even allow the players to go down there until they meet these requirements or they're going to die.
Don't allow until they are at least at party of 4 and level 5 or 6, or party of 6 at level 4 or 5.
Pretty much the opposite of who Larian are as developers. Giving players options and freedom are core values of how they design games. I suspect that if they were acting as a DM hosting a tabletop game they would choose to make it as creative and free flowing as possible and would homebrew or fudge to make it a fun and memorable experience. You have to remember Larian are first and foremost creative entertainment artists, they're not bureaucrats obsessed with rules and procedures. So far their instincts and designs have been pretty darn successful as evidenced by sales of their various products. I think anyone expecting them to make the game more limited and restrictive will be disappointed.
