I've stayed around that time of year three times. Invariably, it's a mixed bag which is kind of nice. There are some cooler days which make for great park days (although the nights can get chilly. For me it's worth it to rent a locker and bring some warm clothes) Additionally, there are usually a few days in the mid-80s which make for great resort and pool days!
Just do yourself a big favour if you haven't already and get your tickets for MVMCP! It's well worth it. :xmas: