If in doubt, winterize. Always better to err on the side of caution than to think all is well and be blind sided. Winterizing the water lines takes all of 10 minutes tops! And takes 2 gallons of RV antifreeze - TOPS!
We travel from Indiana to the Florida Pan-Handle, or Indiana to South Carolina every week of Christmas and the 2nd week in March. One time in South Carolina (in March) did the temps get down below freezing, and we did not winterize.
Our normal routine is to watch the weather reports and if predicting daylight temperatures to drop to 32 or below 3 days in a row, I winterize. We use our camper all winter long in addition to the two winter trips in December and March. So, usually, the beginning of November, or middle of November I'll winterize. Plan the December trip. Unwinterize at a KOA in Tennessee for an overnight, and good for the week we are in Florida.
We then head back North, and when we reach Tennessee again, spend another overnight and winterize in the morning before heading back to snow country.
Then in March, we'll head for South Carolina. Again, we like to do an over night at a KOA in Tennessee (and they have full hook-ups working), and I'll unwinterize. Go on to our destination and enjoy the week. Then watch the weather conditions VERY close, and may winterize again returning home the 3rd week in March, only to unwinterize again in early April, as the Indiana State Parks open up with water again.
So, it's not uncommon for us to winter and un-winterize 4 or 5 times a winter. It's so easy, takes virtually no time, doesn't cost but a couple dollars for a gallon of RV antifreeze and gives peace of mind.
So, like I said ... if in doubt ... just do it and don't try to second guess it.
FYI, considering you are in Florida, if weather is predicted below freezing during the day light hours, I think I'd just use an air compressor and just blow the lines out. I've done this too, in combination with the RV (pink stuff) antifreeze.