It kind of depends on when Presidents Day falls. I would avoid that week as it tends to be much busier than the ones around it. At least during the last year value season was pretty much only slightly less busy than other times it seems as far as attendance.
As Kylie's mom mentioned Nov. is nice b/c they usually have some of the holiday things going on, the weather is usually a bit warmer than end of Jan./Feb. as well. Although in Florida our winter is completely controlled by cold fronts, so it's sometimes just a matter of luck on warm or cool weather. Typically Jan. and Feb. are a bit cooler as the colder air hangs around longer than November (but it can still be relatively cold in Nov.).
If you like getting in the holiday spirit I'd say maybe opt for Nov. as Kylie's Mom mentioned.
