We live in suburban Cleveland. Over the past 5 years, we have driven twice and flown twice to WDW. There are pros and cons for each.
I like the "control" you get from driving. On our first trip, we decided to stay an extra night. Couldn't have done that if we'd flown (unless we spent lots of money to change our flight.) Telling our ds we were staying another night was a very magical moment. Also, while it's unlikely you'll have flight delays, due to the time of year you're going and the weather in Fla. and the fact that the flight will most likely be a nonstop direct flight, but it can happen. I was stuck in Tucson for 2 extra days last year b/c of high winds in Dallas. Messed up the whole country.
Another plus to driving is that we can bring lots of stuff with us. We brought lots of food for the road AND for our room once we arrived at WDW. I brought a bottle of wine and dh brought is vodka and vermouth. I brought my favorite pillow. We didn't have to mess with finding a grocery store (and a way to get there) when we arrived at WDW. When we flew and rented a car we drove to a grocery store, but when we took ME, I packed a suitcase full of food. It was doable, but not as nice as packing our car with stuff from home, especially with the new liquid regulations on planes.
We also stopped at a couple other places on the way home. On another trip, we stopped and visited other family in Florida before Disney.
I thought the drive didn't seem that long and we arrived fairly rested. We actually had lots of nice conversations in the car and ds kept himself busy. We didn't even have a dvd player. One year, we left on a Friday night and stopped in W. Va the first night. Stopped in Kingsdale, Ga the 2nds night., just 2-3 hours from WDW GOt up early and we were at WDW by 10am. The 2nd trip we left in the morning and drove to Charlotte, NC, got to Fla. the next evening. We've stopped for one night on the way home. Years ago, we'd drive straight through to Fla., and drive all night. Too old for that now. I'd be too tired on arrival (or have an accident.)
The advantage of flying is that it's so darn fast and saves you a couple days travel time. The first year we flew, we used Magical Express and didn't rent a car. That worked out great. You might consider that. I bet you can get airfare that's under $200 rt pp. We've flown both Continental and Southwest and never paid over that and we went during spring break.
The other time we flew, we rented a car. That cost a bit more, but you have the convienence of a car. We needed it to visit family, but if we'd just been going to WDW, we would have gone with ME again.
Either way, you're going to WDW! You could always plan for driving, but keep looking for airfares. I wouldn't be surprised if you found a good one closer to your date.