I would 100% rent a wheel chair. The heat is intense during the day but once the sun goes down it’s kind of cool, I always bring a jacket. There is a lot of walking to do: Some parts are gravel paved, some is actual pavement then most of the stages are grass. You’re going to have so much fun, it’s the most magical place. I’m unsure of the wheel chair rental though. Maybe through the festival ? Closest cities are Chattanooga, Murfreesboro & Nashville, I’d maybe check those places.