AFAIK, Florida has some of the most restrictive laws on solar generating for residential use. It makes no sense for one of the sunnier climates in the US but the Utilities got their ducks in a row and helped make the regulations rigid.
The Solar Generator you linked to is just a 90AH Lithium battery pack, a 120V inverter, and a case to carry it all in. It won't run much on 120V for very long. A propane powered generator will get you out of the gas lines after a storm but it, too, will eventually run out. Storage is going to be key to what you need. IMO, storing Propane in steel tanks is easier than storing gasoline. You'll have to do the math to how much you need to stockpile.
If you want RV solar, that is surely easy to do, you're only limited by roof area or what you wish to haul. FWIW, I have a 235W panel and 300AH of battery capacity. As long as the Sun shines, the system powers my 120V fridge and 120V entertainment gear, along with my modest 12V loads. I am thinking of adding more in anticipation of using a small 120V A/C window unit for a few hours a day. Up here, in MN, an A/C is hardly needed but it occasionally gets hot and humid. Nice thing about the Keys is there is usually a breeze. If you can stay clear of A/C, RV solar is easy and a good upgrade.