May I suggest you take a look at some of the rot restauration threads up in Truck Camper University? That is a sticky thread at the top of the forum page. It will give you an idea about what you are getting youself into. It is much more work than what it looks like.
The driver's side corner is probably no better than the passenger side. It just has not given away yet. When you load the camper, I would not expect that corner to be any more structurally sound than the other side.
To move the camper you will need to build some temporary structural reinforcements and attach them to the camper structure where it is still solid. Some disassemly is probably needed to find out where that is.