Yeti, I talked with the folks at Mountain Meadow Resort a couple of weeks ago when I was up there wandering around. They were happy to know we were considering them for a location and they remembered us. At the time, the week of the 13th was wide open for reservations. I asked about the possibility of group rates and they were open to the idea. They asked about how many, I figured the fall rally would be smaller than the spring so I guessed at around 40 people. I've always liked the Deerfield area and am kind of partial to it. I do believe the nights could be slightly cooler than that of the lower elevations.
My 2-cents; there's lots of ATV trails that are similar to single track. Plus the usual two-track roads, and the normal gravel roads. Also there should be a pretty good chance of seeing elk around there at that time of year. The ATV trails did seem to be popular at the spring rally, or at least I heard lots of favorable comments. I do think the area also benefits newer riders and love-boat riding. Don't get me wrong, there's still plenty of rocks!
Okay, there's some info and its obvious where my vote is at, but I'll go anywhere, as long as I don't break something before then. LD