We will be driving, so we have a plan.
#1: I will be packing anything I can early in July while they are visiting their grandparents for a few days. This will be hidden in the garage.
#2: Night before we leave I will pack the clothes and other stuff (I will have a list made of what is needed so packing will go quickly).
#3: They will wake up that morning to find a wrapped box. Inside will be a note from Mickey Mouse, a Kids Disney Guide book(for them to read on the way down), and autograph books.
We have all of our dining booked for the week (the sit down meals). On the day we arrive (we will be there early in the morning), we have the princess boutique scheduled as well as dinner with the princesses. We think that DD#2(4 now, but will almost be 5 when we go) will be so excited her head will explode and although DD#1 announced last week that she no longer "is into princesses", we have a feeling that will change when we get there.
Thanks for the replies and allowing me to share my excitement.