Bunzar Consulting has plans for "RV Chalets" which are similar to the homes with doors that hide the fact that section is a garage. Other states are less strict, so you wouldn't need a 3 hour fire door.
The concept is less of a house with a RV parked in a garage. It is essentially an enclosed, fully ventilated FHU spot, with a building attached for storage and perhaps additional facilities inside the annex such as a large stove, wood furnace, washer/dryer, and fridge, and in Texas, well air-conditioned.
One can go from there and additional storage, but in no case, this is an actual house, but more of a glorified shed.