We leave in a week too and our kids don't know (again)...lol
We are planning on waking them up on that Friday doing a scavenger hunt with them (a quick version). Simple clues like a place where the ocean meets (they know its our bathroom) so they get their tooth brushes and then the next clue is the in our kitchen and then our final clue is our closet where there will be a sign hanging that says we are going to wdw....One of us is posting the sign while the other parent is overseeing the kids