^^^ just one data point:
I was a NJ resident when NJ banned EBR's. I visited a friendly Pennsylvania gunsmith/gunstore, and we came to a deal whereby I leased the floorspace to place my own gun safe. I loaded my collection of EBR's into it, and that was that. When I wanted to shoot I went there, opened the safe, grabbed what i wanted to shoot, and went on my way. Returned them when I felt like it. This 'smith made a small extra busines out of this from about a dozen or so guys in the same position as me. Really, you could do it in a mini-storage place if you wanted to. Security at them is pretty good, and many are climate controlled. Bolt a safe to the floor of one and that's that.
This was/is a way for NJ collectors to store their Class 3 stuff as well, setting up a trust in PA and then storing the assets of the trust in the same state.
Glad I moved...