If you need a bit more space than a Van, Truck, Horse Trailer, or Bus Conversion, why not convert a Tractor Trailer? Several people do this and travel in their own circles.
Most can't fit their rigs in all State Parks, but there are larger campgrounds that they frequent and have plenty of room to park their rigs.
Here is an article about one couple who converted their 18-wheeler into a home on wheels. They even built their own operating train inside. Check it out here.
https://www.busconversionmagazine.com/.../from-barracks.../
