A few years ago, on our first month-long stay in warmer weather, we discovered the beauty, and COLD that is the Florida panhandle in January. I'm from Michigan - and feel like a damp, windy, low-50's day feels colder than a "dry" 20 degree day back home. Since we didn't have heated tanks, we found ourselves many times, adding antifreeze at night to the tanks, just in case....
The next year we stayed north of Orlando, and found better temps, but still had the occasional nighttime winterization of the tanks.
Last year we stayed south of Orlando, and had no problems. LOVED Bonita Springs (near Naples); and ultimately bought a condo near Melbourne :-)
To the OP: a little note about Navarre Beach: it get noisy. Eglin AFB occasionally does weapons testing and "night operations" which sounds like WWIII at about 2 AM! The locals are used to it - but WE sure weren't.
