Hmm, how about something a bit closer to Tennessee and below the cloud-line? My vote's for the area around Lake Conasauga. I don't know about OHV trails, but there are some pretty gnarly forest service roads to start out on. (even running the asphalt up on in the Cohutta's can be challenging and scenic). *Plus I've a small cabin in nearby Ellijay with a little Class 2 &3 whitewater.

early-mid September? Hmm, Labor Day weekend?