There's definitely plenty to do outside the parks! While I haven't done a park-free trip in a while, here are some suggestions I have that may make a long weekend outside the parks more enjoyable.
Renting watercraft and Surrey bikes are fun ways to spend some time, especially if you're staying at BWV. Bike rentals are available right on the BW and can be a lot of fun as well as a decent workout (that bridge by the S&D is surprisingly steep...), while you can rent a pontoon boat or SeaRaycers over at the YC. You can take them around the lake and down the waterway towards DHS. They're so much fun! You can also rent watercraft at the MK area resorts if you want more space to use them.
I'd also recommend heading over to FW if you're interested in other outdoor recreation. You can go horseback riding there in addition to going on a fun run or nature walk down some of the resort's pathways. If you do head over there, I'd also recommend the Hoop-Dee-Doo Musical Revue. That's a great dinner show, but if that's not really your style, you could also head over to the Polynesian between Tuesday and Saturday for the SoA Luau. While it's definitely an acquired taste, it's still a good time. There's also Trader Sam's at the Polynesian, which is a fun (very Disney) place to grab a drink at night (I believe it's adults-only after like 8pm) or there's a nice patio to eat at that faces out on to the lagoon.
In fact, in the MK resort area, you could eat at one of the resort restaurants (like Narcoossee's, CG, or even Kona) and then watch Wishes from the beach or a viewing area at the resort (this would be the beach at the Polynesian, the boat dock or marina at the GF, or CG or the fourth floor observation deck at the Contemporary). You can even catch the Electrical Water Pageant, something that most WDW guests miss. If you're looking to grab dinner somewhere else, you could always just go monorail resort hopping and grab drinks at their different lounges.
Also near both MK and Disney Springs are the WDW golf courses. Most of those I talk to who golf say that the best is the Palm, though if you're not an experienced golfer (much like me!), the Oak Trail course is great for beginners. I'd add that, near the S&D, you'll find Fantasia Gardens, a personal favorite spot of mine. This mini-golf course has two sides: a fun, more traditional mini-golf course and then another really challenging side that basically resembles a miniaturized actual golf course. I've only walked by it, but everyone tells me that it is a real challenge, even for actual golfers.
Over at Disney Springs, you could alway go bowling at Splittsville and catch a movie at the AMC. Honestly, the new additions at DS have really grown on me and I could easily see spending an entire afternoon/evening there shopping and eating at all the food trucks and kiosks. You could even top if off with a showing of La Nouba. I know they've been offering lots of discounts lately, so you might want to keep your eyes out for a general public for Disney Resort Hotel guest special offer.
You could also book a treatment at one of the WDW spas. I've heard good things about the one at the GF, but there's also one at SSR. The one closest to your resort would be the Mandara Spa at the Dolphin. I've not spoken to anyone who's ever gotten a treatment there, though I think the prices are a little less overpriced than Disney's (While I haven't gotten a treatment there, I did just walk through part of it a few days ago and it looked really nice).
Finally, back at the BW, Jellyrolls is a dueling piano bar that I just got to experience for the first time a few days ago and it's wonderful! I really enjoyed it, but I also enjoy the whole vibe of the BW just after sunset. There's three acts scattered around the BW performing throughout the nice as well. If you want to catch a game, the ESPN Club is another fun spot to go, especially if it's a later game, but be prepared to wait if you're getting a table around gametime. For dinner, Flying Fish was just recently renovated and I could not recommend it more! Another fun place across the water is Beaches & Cream at the BC. Make sure to make reservations for both!
These are just a few things you could do. You could also book a fishing charter, fireworks cruise, visit Sammy Duval's at the Contemporary for water sports, do the nighttime animal viewing at AKL, book one of the tours that doesn't require park admission (like Backstage Magic), etc... Bottom line: there's lots to do outside of the parks at WDW!
