Hi,
Last year we went from Jan 2-9. The firswt 3 days were crowded, and then crowds tapered off nicely.
I would suggest go to Magic and Animal Kingdoms at the END of your trip.
Also, we are prepared for the cold , but not the DAMP cold that prevails in Fla in the winter. We are used to low humidity here in MN. during the winter. So on cloudy days and/or when the sun set, we were chilly.Take some lightweight knit gloves along.
Have fun.,
herc.