Wow! Recommendations all over the WDW map! For non-park visits in between APs (including pre- and post-cruise), we've stayed at AKL, Dolphin, BC and BWI. We have three boys, ages 6, 12 and 13 and as much as we love Poly, there is no way we'd stay on the monorail loop with MK in plain sight unless we were going into the park! I thought AKL was great for a one-night non-park stay, and we loved the pools, Sanaa and Jiko, but we prefer a resort area that's more walkable and has more activities and dining options.
So, as difficult as it is to be so close to Epcot and not go in, BC is our #1 choice for a non-park visit pre- or post-cruise. There's SAB, boat rentals (fun!!), shopping at YC, BC and BWI, and all the great dining options around the Epcot resort area. With bluezoo, Il Mulino, Yachtsman, Kouzzina, Flying Fish, Beaches N Cream, Big River Brewing, ESPN, and more . . . there are just so many great choices within walking distance. And then in the evening we watched some of the high Illuminations fireworks from the bridge between BWI and BC. We also love BWI CL, but BC ranks higher under these circumstances because SAB is the perfect pool for a non-parks stay!