Obviously, I'm not an attorney and I haven't verified this with one, but I've heard in my state you can charge a storage fee (equal to a month's rent) for holding their property, charge them whatever amount your lease says for releasing fee, and then add on whatever damages the deposit won't cover.

Converting the back to RV/boat storage and renting the front out.

I'm looking do do flips, lease options, and multi-family, as well as self storage...

And if you find a good one you can even walk away with a big fat check at closing.

It’s a four plex and the garage is being rented out as storage to non-live-in tenants.

We have slowly acquired a small self storage facility, an 8 unit apartment, completed a large rehab project, and turned our previous personal house into a rental after moving into the rehab project. 

Fat fingers.

@Michael Palma  Mobile home parks are second ONLY to storage facilities with ease of financing.   

Is there opportunity for additional bedrooms, adding storage, things like that?

Several options ..Could you build a storage unit on the lot or could you sell the lot to someone who would like to build a house on it .