For my family it's 20-25 minutes. I think it depends on how fast you walk and who is in your party. But it's super close to DCA, like 5 minutes.
You could also take the monorail from DTD on the days it's running. The walk from PP to the monorail is maybe 8ish minutes? The in-park stop is in Tomorrowland, so that's where you'd be dropped off or get on to go back to DTD.