My thoughts:

Arrange to get the battery maintained. Store it cold. Do not ground
run under any circumstances. But when you get back, preheat the hell
out of it before starting. It is the only thing that can help the cam
system assuming you have no prelube system.

I've let my 172M sit hangared cold (MN cold that is) for 3+ months a
couple of times with minimal preprep more than some years ago, and have
seen no subsequent ill effects. But I always make sure the oil etc is
warm before starting.

What's needed is a compressed air powered gadget that can be slipped in
the oil fill tube which will aspirate & spray oil into the upper
crankcase before starting. Anyone have any further ideas?