Powered trailer dolly instead of an RV garage?

A front mounted hitch on your truck may solve your problem but without the layout of the property and knowing the angle of the slope, It's difficult to advise. If the mauevering is done on flat surface, a tow dolly may be just the right tool.

FWIW, I've moved my old pop-ups with a garden tractor. It's possible but on flat surface only. For a small bit I had an electric tractor. That thing could tow anything.