Here's an easy idea to run a campaign. Temple of Elemental Evil, A series, then GDQ. Prep work is kept relatively low and I can work to expand the modules' sandbox aspects to be more like T1/Homlett. It's not exactly original, but there is plenty of room for creativity and a personal touch, plus enough material to last for years of sessions.
Concerns: The modules would be pretty damned tough for a 4 person party. I don't think anyone else in the group has played these modules before, but they may have read them. I would have to check up either way.
It is still a promising campaign idea and can easily be a fun game, regardless if I don't have a big personal stamp to put on the design.