You *could* do it in one day - especially if you have two or more drivers to switch - but it would be a heck of a long day. The upshot is, if you leave at 3 in the morning, the kids fall back asleep in the car and you get a good 4 hours or so with them sleeping, and then more sleeping that night until you get there about midnight-ish.
(And for anyone who thinks you can't, my DH and I drove from the Atlantic Ocean to Winslow, Arizona without stopping except to eat, stretch breaks, and take the kids to the petrified forest NP)(That being said, I would probably never do that again - 44 straight travel hours - woof!)
The trip would be about 1200 miles, and if your car gets about 25 mpg highway thats about 50 gallons, and at $4/gallon that's about $200.
at 9:08 AM on May. 11, 2011