My thoughts are do you really want to spend 7 hours of listening to "I am so bored".
When we travel everyone has 1-2 electronic games, the 4 kids share 2 DVD players with headphones on a splitter so we don't have to hear it, they have coloring books, crayon boxes, books to read, the select about 10 movies so they can switch out if they want something different, we have a few toys like dolls or cars but they tend to be non useful due to limited space.
We also stop every 2 hours for either a snack or a meal. We stop at huge parks with lots of running room or McDonalds with very large playgrounds. Kids get sore and cranky if they can't get up and move around. We travel several times a year with my friend. We have a 7 yr. old girl and a 3 yr. old boy. She has a 7 yr. old girl and a 9 yr. old boy.
I would never leave home without a cooler in the van filled with juice boxes, milk in tippy cups for everyone (they can be washed and rinsed out or even reused if put back in the cooler when the kids are done with them), snack stuff to grab and eat with their hands like raisins, chips, granola bars, Oatmeal bars, fruit roll ups, etc...but we still stop for actual snacks for the purpose of going to the bathroom and having playtime. We hardly ever hear cranky talk from the kids. They have had activity time, quiet time, play time with their brain (the electronic games), etc...we always enjoy our trips even cross states for hours and hours.