I will be running a group through Tomb of Horrors from the 5e adaptation in Tales from the Yawning Portal. For those who don't know, Tomb of Horrors is infamously sadistic. The book itself claims that much of the fun is had figuring out how to deal with the horrific things the dungeon will inflict upon you.
This adventure will be like a one-shot for our group, as a brief distraction from the more open-ended main campaign. We might play for more than one session in a row, but we're only playing Tomb of Horrors with these characters, and aren't really in it to get invested in an overarching story. The goal of the adventure for my players is to experience the dungeon in all of its horrific glory, character death included.
However, I'm wondering what I should do in the event that the group wipes out, especially early in the dungeon. If they get trapped in a hole in the ground and starve, it'll be great fun, but after that, I'm not sure how to proceed.
If everyone wants to keep playing, should I just say "Ok, let's start over from the beginning", and let them prod their way through the same traps? That could get dull, and reeks of metagame solutions. On the other hand, having them "reload" at an earlier point takes the sting out of the traps.
I'd appreciate it if someone who has ran a similar game could weigh in - how can I handle a TPK in a dungeon like this in a way that maintains the idea of a sadistic, unforgiving crawl? Will retrying in any capacity make the crawl less authentic feeling? I don't want 90% of the dungeon to go to waste, so I suppose that's why I'm leaning away from "one shot only".
As always, please cite your experience with your proposed solution.