Frm my research, the DTD hotels that are truly easy walks are the Hilton, Regal Sun (formerly Grosevnor), and Buena Vista Palace. The Royal Plaza, Best Western, and Doubletree Suites are farther and a longer walk (although supposedly doable). If you are going to be spending a lot of time there, go with one of the first three. All of the DTD hotels run a free shuttle to DTD in the evening (and parking is free, but I am assuming you won't have a car), but you might have to wait awhile to catch the next one, so I would stick to one of those three.
We are having a family reunion of sorts next month and part of my family is staying at the Doubletree, but its for space reasons ($99 for a large suite which sleeps six - hard to beat). BTW- the Hilton guests get Extra Magic Hours unlike the other DTD resorts, if that matters to you.