We tow from northern Michigan to the Fort, which is about 1,355 miles one way. It takes us about 2 1/2 days of solid driving to get there, but I'll throw in a caveat by saying we have a mini camper, so not one of the big boys. (We get passed plenty by those big boys, so I don't know if that makes any difference).
We have a few things we commonly do--but we're older folk with no children, so your milage may vary:
1) The first day is our longest, so we start off as early as possible. We've packed, gassed our TV and hitched up the day/evening before, so all that's left is to get ready to leave the next morning. We pack snacks and stop for BR breaks, only stopping for dinner when we get to our first nights stop.
2) If we're stopping for the night at a campsite we're unfamiliar with, we usually do so before nightfall. I've learned from experience that if we've made reservations, and the campground (if at a private one) office is closed, you may find yourself at a site that is totally unacceptable. That happened to us at a South Dakota KOA, and I was thanking my lucky stars that the office during the summer was open until 10 pm. If at a campsite we're familiar with, we usually can trust the office to put us where we request--close to BR's, for example.
3) For whatever reason, it always seems to take longer to get from northern Florida to the Fort than one would think. We usually come in from I75, but we used the eastern route on our first trip and it seemed the same.
4) For us, driving more than 12 hours was too much (I don't drive with the camper hitched, so there's only himself driving). We tried to do it in two days and arrived at the Fort over tired and out of sorts. One day we tried driving from Atlanta to the Fort, and it took us nearly 3 hours just to get from the northern outskirts of Atlanta to just north of Macon. Now, we usually try to stop south of Atlanta.