Haven't been in the 3rd week of Feb ourselves but from all I've read online, if this is President's week, it's been getting busier every year. Apparently most northeast schools have a winter break that week.
So given the dates you've questioned, my first choice would be late May, followed by 3rd week of February and putting Easter week dead last. Also, while the weather can be a bit rainy, late May is usually nice and warm for the water parks without the excessive heat and mugginess of summer. HTH.