I'm back! It was lots of fun.
annabelle, I'd consider it summer. With Memorial Day, the crowd levels will be higher than spring. And if you've got all that time, I'd definitely suggest splitting the MK up into two days. And probably Epcot, too. That'll cut down considerably on your waits, and allow you a nice mid-day break, too.
Hope this helps! Thanks for asking.
Sincerley,
Len Testa