What’s the minimum needed to have a useful RV?
It seems to me that there’s a continuum of things that a vehicle rig could have which would make it an RV. You start from the minimum and work your way up to deluxe.
The minimum seems like it would be:
*enough room for a pad to sleep on
*storage for stuff
*privacy curtains
*bug-screen for cracked-open windows
less necessary but still supercool would be:
*battery-powered lamp, fan, boombox/radio
next would be:
*power inverter to run a regular lamp, fan, TV, toaster, microwave
The next step up in wonderfully cool features to have in your RV might involve:
*standing headroom
*potty and porta-shower, either inboard or movable
*table and seating for it
*stove, counter-top, cooler
Next:
*a frig
*a heater
At some point you may well want sleeping for TWO or more.
Then you might want to add capacity to have outdoor seating with weather/bug protection, as with a fold-out table and awning attached to the side of your rig.
You would, of course, want a massive roof rack to stash and haul all manner of goodies. And a stout trailer hitch.