If you land, ontime, at 11am, that puts you at your gate (off the plane) by 11:15/11:20. Then, it should be about 11:35 by the time you are at the DME area, waiting for the bus...depending on bathroom stops, pace of walking. Depending on bus wait, you should be at your resort by 12:30.
BUT...here's the thing. The one time I planned something special, at WDW, for within 4 hrs of my arrival time was the time my flight was delayed 3 hrs!!! I completely missed the event I had planned!!! I arrived just as they were finishing up!!
So....if everything goes fine, then you should be fine getting to DTD by 2ish....I would make an ADR for 3 just to be on the safe side. Now I try not to plan anything that is sooner than 5 hrs after landing time.