That makes more sense. My next question--have you ever driven an RV? I have. They are VERY, VERY different than driving any other type of vehicle, including a SUV, a minivan, a sports car, or even a 28' box truck. (I've driven all, so yes, I can honestly compare)
The RV is by far the hardest of all of them to drive. The high windsheild is, well, weird. They sway something fierce in wind, and driving them in the rain is difficult.
That said, yes, you can probably make the trip in one leg switching off drivers. I would have no one driver spend more than 3 hours at the wheel, with a break every time you switch drivers. I would assign roles though. one person sleeps and is not interupted, period. The next takes on all childcare duties. The last drives. Rotate so taht the person who was sleeping becomes the driver, the driver takes over childcare, and the childcare sleeps. I would leave in the wee hours of the moring, around four or so. In optimum conditions from SOuth Jersey you should be able to make it in 24 hours.
When you get there, checkin. There is no place on WDW property to park and sleep in the RV except the campground. That will count as your first day. If you are getting Length of Stay (unlimited Magi) passes, they will code them to start the next morning for you if you get there late in the evening.
When in January are you going? We're flying down on the 8th or 9th, I can't remember exactly.
Anne