Hello Jennifer! Welcome back to the Disney Parks Moms Panel.
However you choose to surprise your kids with your upcoming trip to
Walt Disney World Resort, I can guarantee you two things: your kids will lose their minds and you have a lot of (sneaky) planning to do.
On the last Walt Disney World Resort vacation, we woke up our 2 kids, got them dressed and drove them to school. It was not until we arrived that my daughter noticed there were no cars in the parking lot. At that moment, I received a call from a M. Mouse and showed my kids. When I answered, Mickey Mouse responded (a friend of Mickey's I know) and began asking the kids if they could make it down for a vacation. After they responded that they could, he ended the call with a "See Ya Real Soon!" and hung up.
We pulled out from the parking lot and drove away before my daughter realized we were going right then, and she began to scream with excitement. My son took a cue from big sister and screamed in return.
If you leave the surprise for the day of the vacation, you sacrifice the
assistance in planning and packing your kids may be able to provide. As well, you lose the exciting build-up and anticipation that occurs before a Walt Disney World vacation.
I am proud that we pulled off a "day of" surprise for our kids and glad that we did it, once. However, in the future, I will stick with surprises of at least a couple of days in advance.
My recommendation is to do a "day-of" surprise at least once when the kids are young and go for more elaborate and creative in-advance surprises as they get older. If it is your first trip to Walt Disney World Resort, I recommend that you surprise your kids well in advance as the day-of excitement of a first vacation is thrilling enough.
Good Luck!
~Todd