We have a 40 ft. motorhome and tow a van. We find parking at the show is tight, so we park our rig at the Detroit-Greenfield RV Park in Ypsilanti phone # 734-482-7722. It's only about 25 mins. away and well worth it for the hook-ups and safety.
One option is to leave your motor home and trailer at a campground, hotel parking lot, the mall or stadium and rent a van or small truck to drive back and fourth with your inventory. I know other artists that do something similar.