foamie cabin

I know this a strange request, I think this would be possible. My wife, my son and I go to several drag races per year and typically stay in a hotel. This coming year I will have 2 cars to run and I really would like to get away from the hotel. I was thinking a small camper and then the foamie cabin idea came. I will be hauling the 2 cars, tools etc on a open 40' gooseneck. To those with experience do you think it would work to make 4 walls and a roof using the 2" foam boards, make each one connect with dowl rods or some other method. Then put roof on and use a securement method. For interior All I want is one wall to have a door, all others to be solid. I would use a portable AC to keep it cool and comfortable. Make it where they stack on top of each other for transport and setup pretty easy to serve as a cheap 8' x 8' shelter. For those with experience, do you think this is possible? Suggestions how to build the panels?