I have the size smaller than 6 x 4 and am able to lift it so that it stands on its tailgate up against a small fence. I usually get a member of the family to help me but I can do it myself if necessary. I use two pieces of wood under the tailgate to protect lights etc and then tie it to the fence and also put a chain and padlock on one side as well. This is so that it cannot be pinched but more importantly so that it cannot fall if the ropes are undone by some smart alec kid.
I would not like to lift a 6 x 4 however.
If you have some structure overhead nearby you may be able to rig up a light block and tackle arrangement to help you.
"It's good enough" is low aim