Wow LL you're driving now?! With gas and potty breaks (and don't confuse the 2) it took us about 24 hrs total on the way down and 23 on the way home. Its really a straight shot once you get past NJ. Make sure you start your toll money fund!
Once you renew your AAA membership, request a TripTik. We had this, plus a regular road map and our GPS. Made me feel much safer to travel that distance! They will also give you tour books with nearest hotels and information that is also very handy to have.
One thing we learned about that fuel cost website, is that it takes the cheapest gas in that area. Usually the gas right off the highway is about 10-15 cents higher. Keep that in mind
The no restraints packing is a major plus, especially on your way home you can fit so many more souvies!