Just A Car Guy: amazing, semi trailer converts to carnival ride. The Rabbat family F1 traveling carnival ride
Wondering how to make an expandable unit? You could do worse than this:
It appears to start the size of a 40ft shipping container, and expands to maybe 56x24ft.
I could see a 20ft hi-lo trailer with with a pop-up pedestal in the center with the bath and kitchen, and 5ft drop sides that expands to 30x18 with a 8ft ceiling.