I took my then 6mo in Sept. We were staying at BWV, and everyday after lunch we'd go back to the room for her to nap. I think it was only truly successful once. The other days it was just an exercise in frustration, and she is typically a good sleeper and we'd loose 3-4 hours. She'd fall asleep on the bus, then wake up when we got off or similar. On that trip she did sleep well in her stroller at unplanned times, which was nice even though it affected our plans. We got this before we went, and threw it on the stroller when she went to sleep:
http://www.toysrus.com/buy/gear-accessories/babies-r-us-baby-shade-cover-1934049-18166366 it helped a lot, because she likes watching people.
On our last trip in Feb with our then 1yo we had planned on going back to the hotel (Wyndham Bonnet Creek), but we ended up getting her to sleep in her stroller pretty well in the parks and she seemed pretty happy with it. We'd feed her lunch, lay her down in the stroller, give her a bottle, after she finished the bottle we put the blackout cover on and she was out, while we walked and talked like normal. I also take a baby harness (chest carrier) and she falls asleep in it pretty well and can stay asleep in it throw all kinds of movement. If she was in her stroller DW and I would do some baby swap rides while she slept.
One great trick that has worked 6 out of 6 times. Every time we take her on The Haunted Mansion, she konks out, since she is in her harness we can go about our normal activities and she stayed asleep. This last trip, she was really going nuts, because she was overly tired, I got a FP for HM, took her in there, she went nuts all the way until the elevator scene and boom she was out.
BTW: Our travel stroller is a Chicco Liteway, that can lay almost completely flat and gives her enough room to stretch out without being bulky around the park. If your baby isn't used to sleeping with noise, I'd try to train them before going to Disney.