Pushing a TT into position from the rear bumper...?

Those jack-wheels do make it possible to move a trailer by hand on a hard packed surface, but sheets of plywood work, too.

If you've got some mature trees, you might also be able to use a winch or come-along with a block & tackle. It would be slow, but relatively safe.

FWIW, I've seen 2" receivers welded or bolted to the rear frame on fifth wheel trailers to allow triple-tow where it's allowed. That might also be an option to consider in conjunction with a jack wheel.