One set of tires *should* be enough, as long as you don't flat spot them. Are you taking the GT1 car? I used to crew for a TransAm team, and although the tires drop off, they were never corded - This is with 4 30 minute practice sessions and a one hour race, although we did use old race tires for practice and new for qualifying/race (so probably 3 hours of track time on each set before we gave them backt o BFG to get disposed of). I'm not familiar with how quickly your car wears the tires. The V710's on my Camaro last a few weekends, fwiw. The first day track time will be in 20 minute blocks (4 run groups from 8am-12:30pm), and if everyone cooperates, we might combine the instructors/advanced group together for a longer last session as long as the track isn't too crowded. Friday afternoon we plan on running an open track format 1-3pm, and limiting the total number of cars on track. They'll be let on in a first-come basis, and if there's no one waiting in the hot pits to go out, you can run as long as you want. If there is waiting, we'll ask that you bring yourself in to let other cars out. This should get a ton of track time. We'll break at 3pm for parade laps to get some of the "floor it for 1320 ft, slow down, and turn right onto the return road" crowd hooked on road racing as we set up for the time trials, and then do time trials. As soon as everyone entered for the TT has finished (half lap warmup, 3 hot laps, half cooldown, group of 3 cars released in 20-30 second intervals), we're back to open track.
We will run in the rain as well, so try to have some kind of non-slicks available just in case. It's a great learning experience. The Grants Tomb arera gets very slick (drag race launch pad) in the wet, so we might run the cars slowly down pit lane instead.
The track has race gas, but they usually just open the pumps once a day - we're trying to get them to do it more often, or at least open it first thing in the morning. If you run pump gas, the gates will be open to let cars through in between each session, so you (or whoever volunteers) can get to the BP gas station a mile from the track, fill up a few fuel jugs, and return to get back in 20 minutes later.
Does your car have a passenger seat? I'd love to get a ride!
Andris