We've done this twice and absolutely loved it both times. During those trips, we were a family of four (we've since added a fifth), and our girls loved it both times. They could probably swim in a pool for 12 hours and call it a great day, but we sprinkled in a few fun meals, watching nighttime spectaculars from outside the parks, and really digging into everything that the resorts have to offer that you never have time for when you're at the parks.
AKL is, by far, our favorite spot for this type of trip. They used to have activities where kids could earn beads; I don't know if that's still a thing post-COVID. Regardless, it feels different to sit on your balcony and watch the animals eat breakfast when you're not missing something at a theme park.
We also had a no-parks day (really two) at BCV, and Stormalong Bay brought more than enough to the table to fill two complete days.
If we had a full no-parks day on our upcoming trip to BRV, we'd swim, take a tour (is that back yet post-COVID?), have lunch at Geyser Point by the water, make a dinner reservation at Artist Point, then find a spot to post up for the Electrical Water Pageant. And we'd feel refreshed instead of wiped.
Don't get me wrong; I loved feeling exhausted at the end of a good Disney trip. But I've also found tremendous joy in peacefully wrapping up a no-parks trip. I think our longest was six days and they were six truly delightful days.
EDIT: I forgot to mention that we didn't even go to Disney Springs. I don't like DS, so nothing was lost there. If I had my complete sway for a no-parks trip, it'd be at least two nights at BCV followed by at least two nights at AKL followed by one night at BRV/CCV/PVB (so we can easily get to the Poly to watch HEA on the bluff overlooking the bungalows).