I don't know the exact answer to your question. On paper it looks like you have plenty of room once you get the hang of maneuvering the thing. I will say that practice will indeed make perfect. I moved into a new house the end of 2015. I waited several months before bringing my motorhome to the new house because I was terrified of parking it there. The driveway is almost 500 feet long, it's steep, and the turnaround area at the top is pretty much the same size as the motorhome squared (like a 30x30' square). I have enough property to park it, but I need to get it turned around at the top.
The first time was terrifying - I got it to the top, nosed up against the end of the driveway and then came the "now what?" moment. Well after a lot of maneuvering I got it into its spot.
Fast forward to today, I can drive up and swing it in its spot in one turn. It's tight, but it gets easier every time.
