The pools are all heated, but even Mickey can't control the air temperature.
I would say a definite "probably." If the weather's nice when you arrive, plan on swimming then. If you decide to postpone it, you may not have another chance.
The water is warm enough, but have your towel close by to wrap when you get out- especially as the sun goes down. I can't speak for daylight hours, but we swam early eve and early afternoon. Daytime temps were in the upper 70's while we were there over the last week of Nov. 1999 and cooled down to upper 50's to low 60's overnight. It was comfortable for touring, but not water parks IMO. (we stayed away from the WP's)