Ok I see your thinking, but to ensure you build that set of family memories make sure there is more doing and less seeing for the kids. If both you and the DW are sharing the driving, your both "doing" the kids though are still just "seeing". Plug in a theme park every couple weeks, Ball game was a great idea, and personally I would go as far as Vegas, there are 2 or 3 days worth of family activities there as well, and then turn north to North rim of GC and up to Wyoming beore starting back east.
Also you havent made any comments about family activities normally, Do any of you like climbing, fishing, animal lovers? Plug in a few of each of your favorite things to do. Everyone gets involved in selection and planning.
I guess the biggest thing to remember, going fast and striving to accomplish are what you normally do for about 50 weeks a year, your RV time is when you dont have to, you "choose" to.
