Glad my inclination with multiple characters was correct. I didn't consider that with regards to saving throws. A carrion crawler or a grell becomes a truly horrid beast! I was thinking of things like forcing one character to be a fighter (if not a multi-class) for sweep abilities, giving one character psionic access (as long as they have Int/Wis/Cha above 16), and that high-ish starting EXP to distribute across characters to give them a fair shake. Maybe I'd run a level 1 henchman or two. However, gentle AD&D seems like not AD&D at all. Much to consider! Semi-related, I recall vaguely reading an account of a session that was just sending a lone level 15-ish MU into the Caverns of Thracia - I don't plan on doing anything THAT outlandish!