There is no way way to accurately predict what airfares will be this summer. SW and JB tend to wait until 3-5 months out to open their booking windows. The larger, legacy airlines start booking 11 months (or so) out.
Here's the thing to keep in mind when deciding which is the better way to go...flying vs driving. Time. How valuable is your time to you? Yes, you have to pack lighter, and possibly do laundry once while in WDW if you fly. But, you have a lot more time to actually spend there!
When looking at airfares, it would seem that you want to keep it below $1000. So, go out and see what the legacy airlines are charging for the times you want to go. Wait until the other airlines open their booking windows, then make a decision.
Strollers will be checked at the gate. Your child can remain in the stroller right up to boarding time. Then, as you walk down the jetway, just before you get on the plane, you will hand your stroller to the airline person there. It will have been tagged at the gate, prior to boarding. Then, when you get off the plane, and airline worker will have it out for you. You may have to wait a minute or two until they get the strollers up to the jetway, but it's very easy to do.