At first I doubted your claim about saving $ by renting in FL, but after crunching some numbers it looks possible. It's 1500m from Bangor to Orlando. At 10mpg towing, you'd use 150 gal one way, doubled by return trip. A sedan getting 30mpg would use 50 gal each way. That 200 gal round trip difference @ $4/gal leaves you $800 ahead to put toward a rental. When you add nightly camping fees into the costs w/ your own unit vs. they're likely being included if you rent a park model; you could well end up saving $.
Wife & I are snowbirds. Previously wintered in FL but spent last 4 in the SW. Thinking of doing FL again this Winter, however, for a change. (Hope it hasn't filed to capacity in our absence
I can't give any suggestions for park model rentals but as I assume any such rental would be in a park, likely gated & perhaps patrolled, that safety wouldn't be an issue. In FL we boondocked in the 3 Nat. forests & also camped in state forests, & on federal land like Big Cypress & never feared for our safety although sometimes we seemed pretty "out there" w/o any other campers around.
FL, especially South of Tampa gets hoards of snowbirds & private parks charge accordingly, especially near the coast. Camp prices in keys were sky high 5 yrs ago & likely worse now. Early reservations are a must. Expect to pay double for any campground w/ word "Resort" in their name. It's a huge state, though, & away from the busiest tourist areas you can find a safe & affordable place in the sun.
If you do tow your Sunline down & wanna use it to move around some rather than spending your entire stay in one location, I'd be happy to provide some additional details. Have a great time !!!