I spent a long time as a youth trying to design such a thing. Lack of money, materials and mechanical skills prevented me from going from note pad to build.
The example you post is too wide and, I'm sure, too heavy.
The way to go is a trailer tent. The base should fold so the towable size is not much bigger than a conventional trailer. The top would either be tent poles curved to form a cowboys and Indians style wagon roof or some sort of articulated pram hood construction. In either case you wouldn't be towing a full height mini - house with all the visibility and windage issues that would entail.
Hmm. Maybe I should give it a bash. Nice garage engineering project.