I did learn a few things.
New ideas that worked well:
1) Change up the seating arrangements partway through.
Since we have four kids, we have two in the middle row of our van and two in the back. Partway through the drive, I swapped the baby and the oldest, so the oldest and toddler were in the middle row and the 5year-old and baby were in the back. (Make sure you're comfortable removing and reinstalling car seats if you choose to do this!) Since the two oldest were prone to fight after spending too much time in the back together, this broke up that issue. It also enabled each of the older two to help out the younger two.
2) Individual lunch boxes full of snacks.
We went to Target the day before the trip and picked out different sorts of snacks. We then packed each kid his own lunch box with the same set of snacks. They could keep their food with them and eat what they wanted whenever they felt like it, and I didn't have to be handing around food while driving or policing what anyone was eating. This was an especially good idea since I was driving alone and didn't have an extra set of hands to help with the passing out of food.
3) Gallons of water and refillable bottles.
Each kid had a close-able, refillable water bottle, and we kept two one-gallon bottles of water in the car. We refilled water bottles at stops. This created far less waste than disposable bottles would have and was more fun. I also found the water tasted less plasticky and was more enjoyable from a reusable bottle.
4) Crayola Color Wonder markers.
My toddler is prone to color on anything within reach, so I bought a travel set of Color Wonder markers for them to use. It was novel, because we haven't used them much at home, and it was neat and clean.
5) Barf bags, emergency clothes, and hand wipes.
I bought a package of emesis bags from Amazon to keep in the car, just in case. I also had each kid pack a full outfit outside the suitcase that we kept in the car just in case a change of clothes was needed quickly. This way, we wouldn't have to dig through suitcases in the trunk to find a change. Fortunately, no one threw up in the car (I attribute this to the fact that we had barf bags available). However, at one of the rest stops on the way home, the toddler fell into a mud puddle and required a change of clothes. Emergency change to the rescue! I also bought a 4-pack of hand sanitizing wipes for the kids to keep near them. These were great for cleaning hands after a snack or after using a gas station or rest stop bathroom with questionable hand-washing facilities.
6) Plan to take much longer than the GPS claims.
Accept that an eight-hour drive may take 10 or 11 hours (it did for us, anyway). Stop when you need to. Use the restroom every time you stop. Eating will take twice as long as you expect. Don't push yourself or the kids. Make everyone (even the babies) get out and run around or move around every time you stop. They're confined in their car seats and need to stretch, too.
And some thoughts for next time:
1) Pack whole outfits in individual bags.
I've heard this suggested and had planned to do it this time but got lazy. Pack individual full outfits in separate bags so that each day the kid can pull out a whole outfit without having to root through the suitcase for what he needs.
2) Bring a collapsible hamper.
If going somewhere where you'll be able to wash clothes, bring a cheap hamper to put dirty clothes in so they don't get all mixed up with the clean ones.
3) Unpack into drawers.
I didn't bother to unpack the suitcases at our destination, but I think it would have been nice to do so. We were there for two weeks, and it got pretty annoying to root through the suitcases looking for clothes. Another option might be for each person to have his or her own suitcase instead of mixing up the clothes.
Do you have tips for accomplishing a solo road trip with kids? Have you tried any of the above tips? How did they work for you?