Gentlegamer said:In the original module, who said you have to fight the demi-lich? Tenser and Robilar sure didn't.
Then why even go there in the first place?
Other than looking for fame and fortune you really are not there for any other purpose so why go there to begin with

There really isn't anything there except the demilich and death.
I have run and played TOH in every version of D&D and without using knowledge that a character would not have you die, usually long before getting to the end.
I will have to read RTOH to see the section you are talking about.
I also think that 3E's expectation of smaller parties makes TOH even more deadly because of the powers of the demilich being more dangerous to small parties.
TOH can be integrated into a campaign but would be a totally different adventure than what was originally intended, especially if modified to match the original levels and "Balanced".