Pop-up camping in Florida during January is no problem. Just get a long-range weather report & pack accordingly. The average high is around 70, and average low in the 50's-60's. On rare occasions, it will drop into the 20's during the night & only reach the high 30's to low 40's during the day.
Make your January plans, and just watch a good weather website about a week before your trip.
One thing is guaranteed. You will NOT have to cope with a lot of snow!!!