G'day GG,
Like Hem's suggestion, First thing I thought of was a drill or something similar to help with the winding of the winch.
There would be some kinda setup out there that could be bought or adapted to to this.
Someone had done an Air Ram push up system, if my memory serves me right, A swagger might know of that thread or who did it.
Maybe a strut for pushing the bed out, not sure how that would be setup.
They are some smart buggars here that may have some idea on how to do this.
Hope you find a solution and you can keep camping & travels.
All the best with it.
Edited: To add about the Air Ram System