We don't mind the cold. This will be my second full winter in our 5th wheel. We are about 45 minutes north of Birmingham in Alabama. We're from Northern Michigan though so most days the winter here is very mild. Most days it doesn't get below freezing, though several nights it does. We just leave our water on a trickle.
Maybe in a few years it might bother me? But right now the summer heat bothers me more then the winter cold. There are several people who full time here, though most pull their campers out for the winter.
I understand Michigan cold! There is indeed a HUGE difference in weather between N MI and central AL! However, I could not recommend ANY location in KY or in eastern TN to spend the winter in a FW. Tom hit the nail on the head!
If you like central AL, why do you want to go north for the winter?