If a person maintains a residence or camper when they leave, there are plenty of creative places to hide a firearm that is packed so as to help protect it from the humidity (if the structure is not climate controlled).
Maybe network some social friendships locally?
When I was in the military, I used to leave my firearms with my neighbor, he was a local deputy. He was more than happy to keep my firearms, it reduced my fear of, and chances of losing, my guns to a burglary. Prior to that, I would hide them in the attic space of where I lived. At that time, I only have about ten long guns and perhaps five or six pistols.