at the moment. So there's a good chance that we'll have to move in a year.
For now, a small 4x8 shed
I had a similar situation when I lived at the trailer park. I needed a substantial shed for secure storage. I built a nice sturdy full-height shed, 10x10 at the base and 12x12 at the eaves. I never gave a thought as to what I would do when I moved. Well, when I did get ready to move, I was able to hire someone to move it for me. I just looked in the phone book under house movers. I was able to hire a guy to move my big shed 250 miles to my new location, no problem. For someone who is used to moving houses, a shed is a non-event.
So if 4x8 is big enough for you then you should be able to buy or build anything you want. You could even look for a mover in advance. I think you should build or buy an extra sturdy shed that will stand up to being towed at highway speed. I lost a few shingles on mine but was otherwise was very happy and surprised at how easy it was to have a rather large shed moved.
Lawrence