We’ve driven from New Jersey and have taken both the inner route and the outer route. The inner route you would be getting on I95 or the NJ Turnpike once you get to the Jersey side from Long Island. 95 is the more direct route but also the route where you will hit a lot of traffic around the cities (Baltimore, DC, Richmond). If leaving on a Saturday you won’t get commuter traffic but may get Jersey Shore traffic. We’ve overnighted in Brunswick, GA. The drive from there to Orlando on a Sunday should not be too bad, 3 1/2 to 4 hours. 95 to I-4. Beware of some of the craziest drivers once you get close to the city of Orlando .... and people talk about Jersey drivers!!
The outer route is taking 78 west in NJ all the way thru Pennsylvania until it reaches 81 south. It is longer mileage wise and is sometimes slow due to only two lanes and trucks, but some people prefer it, as you can take to Virginia and get on 64 which hooks up with 95 below Richmond. The thing of it is accidents, roadwork and traffic jams can happen on any of these routes, so you just never know.
Coming back we’ve stayed in Fayetteville NC. left Disney a little later to avoid the Orlando and Jacksonville morning rush hour.
I’ve driven both routes and have had mixed results. I’ve also flown, but you have a large group and then you’d have to rent a car or get a car service since there is no more magical express. I’ve also taken the Amtrak. Not cheap either for a large group if you get sleeper cars, but I sure did enjoy it. There is plenty of car services that will bring you to Disney from the Orlando station.
Have you checked out the transportation board here on the Disboards? There is a thread for ‘2,000 mile round trip drivers’. Really helpful...just post your plans and you will get lots of advice.