Agree with everyone's comments above. Keep everything in a backpack or even just a sturdy plastic bag that you can easily grab (vs. having to remove every single item from the stroller basket before folding it). Assuming she's still awake, I usually helped my toddler up onto the bus "step", told her to stay, and then turned and folded the stroller with apologetic looks to the people in line behind me. Shove the stroller under the seat on the bus if you can. When she falls asleep while waiting for the bus though, that is rough. Put on the backpack, sling her over my shoulder and pray she doesn't wake up, try to fold up stroller with one hand (lots of practice!) and carry them both onto the bus without whacking her head on anything. Oh the flashbacks...
And if its an option, consider staying at Bay Lake Tower, Grand Floridian, Boardwalk, Beach Club, Swan or Dolphin? Walking distance to a park is amazing... to two is even better. Sleeping kiddo can basically be transported directly to the room.