Flamingomo,
We have been making 1200 miles trips to the midwest (among many other drive vacations)with my girls for 5 years or so and I find that it is tempting to want to push the limit on not stopping, but they just need to get out of the car seats and run or stretch sometimes. We started the 1200 miles trips when DD-7 was 3 and she finally flipped out about 9 hours into our first trip and we needed to get a room for the night.They are 7 and 13 now and when we go to WDW this Nov. we will leave RI @ 5 a.m. and drive 730 miles to VA (about 12 hours- we make 1 -1 hour Cracker Barrel stop 4 hours from home and probably 2-3 more for bathroom/food/gas all in one place to cut down on on/off highway time wasted), then go to Daytona the next day. We'll hit Disney on the 3rd day of our journey.
Going home, we may very well drive straight through if we can do it, but it is nearly 1400 miles for us. The best we have managed is 1150 straight through with 4 bathroom breaks. When the kids go to sleep at night we won't stop unless one of us is about to pop!
We do not go Rte 95 except for leaving home and when we take 26 into 95 in SC. We have hit NY city at 2 a.m. and
still been stopped in traffic so we detour. We will take 95 (RI/CT)-9-691-84-81-77-26-95 (SC to FL). We have learned from probably
25-30,000 miles of travel
with kids

scared1: OMG that is scary to do the math...), that our kids sleep very well when we move, but a traffic jam or construction will wake them up quickly. I'd rather go 100 miles out of our way (as we are) to avoid all the big cities. To us, the time spent driving a bit farther west at first saves us time sitting in traffic. I do not sit still well...
You have all the right stuff with you-- I couldn't do it without my Yukon and DVD player. Snacks are great and don't forget an empty bottle with 2 boys! We traveled with a potty in the third seat up until last year!
Best advice--Hope for the best...expect the worst. Your trip will
still be fine if you arrive later than you hope. But remember, anything can happen and while it can (and probably will) go smoothly, kids can be kids. Then again, moms and dads can be kids too when it comes to being locked in a car with the same people for 16...18...24 hours!
Have fun!! I love to see the country we live in, that is why we don't fly. It is so beautiful to drive. Enjoy it!