Put an entire outfit (including undies and hair accessories) in a ziploc bag. One bag per day. When you get to the hotel, put the bags in a drawer and they can pick one per day. Did this for Disney trip. Put dirty clothes in bag at the end of the day.
The Fun Cheap or Free Queen: How to survive a road trip with two babies by yourself.roadtrip tricks, tips, and creative ideas! (plus link within the site to more tips from a trip w/ slightly older kids)
101 Toddler Activities - Road Trip ideas, games, and hands on activities for kids - parents, keep your child busy and happy in the car on long trips. Perfect for travel with toddler or preschool aged kids.