Fridge would be Calor or Butane gas, of course. Don't know how he would keep it from blowing away, perhaps strap it down to big corkscrew things in the ground either side (available in all good caravan showrooms)
There is probably a Portapotty in a cupboard-sized loo. They are much more sophisticated these days. Between the bowl and the storage tank (containing a far less horrible chemical additive than they used to) is a trap-door that is opened for use and then closed.
So you don't have to imagine him going out and peeing over the cliff edge, PapaOscar, or worse, pooing over the edge. (The mind bog gles)