Like Bansil, I am accustomed to the rear of any RV that I have hanging out in "space". Too many years of camping in Southern Appalachian public parks where the drop off the backside of the campsite ranges from 3 ft to 20 ft? With the popup, we would back into the campsite open it up, set up the "drop off" side and then spin the popup around and back the thing up to the edge of the campsite out over air. Then finish opening up. Loved that hard sided popup. Had more than one park ranger come to watch us break down. In the Class C, we would roll the RV back until the rear wheels would almost touch the back border of the site. My bus may be 40 ft, but it is currently sitting on a 27 ft long pad in a private RV park. As long as there are no obstacles behind the bus, it will fit. You may want to invest in a long measuring tape.
BTW, when I leave reviews for any park/campground, if it is skoolie friendly (I have been asking for quite some time) I say "This is a skoolie (school bus conversion) friendly park" in the review. If you know of any private parks that you have stayed at that ARE school bus conversion friendly, why don't you post reviews of the park (public and private). You don't have to have stayed there recently. But it will get it into print for others to read. RVparkreviews had a problem when I first used "skoolie" hence the "school bus conversion" in parentheses. I was contacted and they supposed to have added that to their spell check. To make things easier on you, you can simply do a general review in notepad and save on your computer, then you can flesh it out as needed by each campground.
BTW, some of my reviews disappeared when they redid their website. If you left reviews, you may want to check to see if any of yours got lost as well. I also just re-registered under a different name.