I am 35 feet and tow a trailer that is 25 feet ball to bumper, so with the hitch I am 61 feet. I would only go to a camp site that I had spoken with the operator and reserved a specific site. I've never actually taken that rig into a camp site, now that I think about it. I've always over-nighted in truck stops, and my destination has always been a race track where I am far from the largest rig. I've seen people with trailers in camp sites, mind you, and frankly they always looked pretty stressed about it. State parks usually won't let you in, but sometimes will let you drop a trailer in a parking lot for storage.
Brian