I don't think the decision to stay at a specific category of resort has much to do with walking distances. EVERYTHING at Disney involves a LOT of walking regardless of where you are staying. Even if you take the monorail going to EPCOT, you will still walk down a long/slanted ramp after exiting from the Polynesian/Grand Floridian/Contemporary monorail, walk underneath the monorail and then back up a long/slanted ramp to board the Epcot monorail. When you arrive at Epcot, you again walk down a long/slanted ramp to get to the park entrance. Depending on how many people in your family are going and the age ranges, you should probably have a discussion about overall planning/logistics/budget & expectations, since everyone may not want to do the same things every day.