In Port Augusta some years back, we parked next to a Scania tour bus which had been converted.
He retained the 'upstairs' where the passenger seats had been, installing 3 swivel leather lounge chairs for SWMBO & friends to enjoy the scenery as he sat in front of the right-front wheel driving.
The rest of the passenger area had been converted into lounge/kitchen/bathrm/bedrm.
The 'downstairs lounge' at rear had also been retained as a TV room.
Luggage area (with parallel-hinged doors) he had converted into laundry/service area (water tanks/genny/HWS/etc) & workshop
complete with workbench & toolracks. It was tall enough to stand up in, although head clearance was about 1cm.
They pulled a trailer almost the size of Girt, and he backed a RAV4 out of it.
I commented that it was an awfully big trailer to house a small 4WD.
He told me there were extra water & fuel tanks in the front of the trailer, and there was a mezzanine floor in it; upstairs housed his
ultralight plane 
...
as you do!