Well, I did the opposite. Walked from DTD to Doubletree to rent a car. Close to a mile. Took 15 - 20 minutes. No big deal and nice safe walk. I have heard rumors on this board that Budget will pick you up at your resort, so maybe if you ask them they'll ride you back to DTD!
It's an easy walk, and the rumor of budget pick-up or drop-off service is true. You just need to let Traci or Seth know ahead of time, so they can have someone available. The local agency number is 407 827-6089.