When we were at SSR in May, we stayed in Congress Park, closest to the bridge. I found the walk to DTD to be quite easy and nice. DH and I made the loop one evening. The villas are closest to the end with the World of Disney, Rainforest Cafe, etc. You can walk all the way thru to the West Side and around back to SSR. It is farther and wouldn't do it unless you want to get some exercise or happen to be on that end of DTD.
Enjoy your stay.