We have driven several times now and love it.
We went last March Break and had no problems with bad weather. We prefer driving over flying - no hassles with the suitcases. The kids like to watch movies and play gameboys
I usually pick up stickers and little activity books from the dollar store - a little surpise bag at the beginning of your trip goes a long way in entertaining the kids.
Also pack lots of snacks - juice boxes, fruit treats, chips - stuff they would normally not have - this makes it more tolerable.
We cross over in Niagara Falls and head down via the I 79, 26 and then I95.From TO about 22.5 hours.
We leave around 3:00 a.m. and try to make it to Charlotte, North Carolina on our first stop. The benefit of stopping there is that it is a large city with many nice hotel options. We prefer the Country Inn and Suites or the Hamptons Inn. We look for a place that includes breakfast.
We continue around 8:00 a.m. the next day and stop for a longer stop in Savannah, Georgia. It has a super wal mart close to the highway.
We then arrive around dinner time at WDW. The kids 8 and 4 push to get there "sooner" but this is about as fast as we can do it. Make sure to stop at the Florida Welcome Center for a sampe of fresh squeezed orange juice. Also the kids love to get the disney pamphlets there and they start to look for Palm trees.
The drive through the mountains is beautiful. The weather can be unpredictable- we've had heavy fog, rain, and sunny conditions all on the same trip.
We also pack a pick nik lunch with us on the way down with PB & Jam sandwiches, juice boxes etc and stop at the rest stop to have lunch.
On the way home it usually takes us a day longer and we look for larger cities on the way home. The only time that reservations were an issue was last march break when all the CDN were on their way back and we stopped at the Outlet Mall in Erie and wanted to shop there. We did get a room at Motel 8 - not our first choice, but it was fine. So if you go in March I would call while on route via cell phone to make a reservation - that way you are not tied to a certain place ahead of time if you feel like driving for a longer period of time.
Don't forget to pack change for the Tolls - there are quiete a few at the onset of the drive. I also take Gravol and a beach bucket, a towel and lysol spray just in case. (We used it the first trip when dd got car sick) The bucket was a life saver.
Enjoy the drive and be safe! We also just bought into DVC and will be doing the trip in December. Hope the weather hold out.
Denise