How exciting! What a great surprise for the kids. I admit that I am an over-packer but on our last trip I really planned what the kids would be wearing each day and put everything they needed in a big zip lock bag, including socks and underwear. It helped me fit everything in and not pack too many extra clothes. It also made it easier for the kids to get themselves dressed in the morning. Doing laundry is always on option so pack quarters and some travel size thing of laundry soap.