Should be no problem. We've been many times in our 30 ft. fifth wheel + the length of the truck and had plenty of room. We've seen some really big rigs in those sites with no problems. We've reserved a preferred site in October in our new-to-us 37 ft. motorhome.
If you ask them to put a note on your reservation that you need a longer space to erect your tent house, I'm sure they'll do all they can to accomodate you.
They've been super helpful to us. Oh, and if you're going in October - buy tickets to Mickey's Not So Scary Halloween Party. It's great.
Happy Camping
