Stand-alone solar of any reasonable size is really only going to be useful for charging batteries which are in turn used to power a load as needed. Might as well set it up to charge your camper battery directly for now, then re-wire to charge whatever battery pack you put in your cabin when the time comes.
Residential solar only works without batteries because it is essentially treating the electrical grid as a giant battery (sell power when you over produce, buy when you under produce). This doesn't work if you are off the grid.