We live a few hours north of Orlando and it doesn't really get very cold for us until Jan. Of course, you could get a cold snap, but for the most part it's 70s and sunny that time of year. In fact, the last two years we have sweated through our local Christmas Parade. We have swam at Disney when it was chilly out and as long as you are in the pool and it's not breezy, it's doable. The kiddie areas feel colder to me, since there isn't as much water. I would probably stick to the deeper pools if it was cooler than expected, but depending on how sensitive to cold your kids are, they might be fine. My ds doesn't care if he's cold, so he'll play in cold water, while my best friend's kid only swims if it's 90+ out and bath water temp pool!