You might have read one of my post regarding where to stay during when.
During winter and especially during the Christmas holiday, I prefer to stay at the WL. The setting is just perfect during that time. It is all decked out with Christmas lightings... it is just breathtaking. This resort has two hot tubs, perfect when it chilly at night.
During summer, I would prefer to stay at the Polynesian. The weather is just perfect for this place. This resort do not have a hot tub, so no worries during the summer, the warmth of the sun will keep the pool nice and warm. With the warm weather, it makes you feel like you're actually on a tropical island.
POFQ is anytime of the year! I haven't gone to POFQ during Febuary and I don't know if they do anything special during Mardi Gras.