Welcome!
So on your dates, there is a Magic Kingdom After Hours on Friday Jan 31st - if you plan to do Magic Kingdom at night, I can't recommend this event enough. My wife and book our yearly trips around these dates. For those days that we're going to an after hours, we don't use plan on purchasing a normal park pass as we can get into MK at 7pm and be there for at least 5 hours knowing 3 of those hours will be little to no waits on almost all the rides ... plus the free ice cream, popcorn and soft drinks throughout the night.
Regarding exploring outside the parks, great idea to visit the Boardwalk and Poly. For the Boardwalk area, look into the Dueling Piano's at Jellyrolls. Really fun nighttime activity if you're into that! Another resort to checkout is Animal Kingdom Lodge (both the Jambo house which is the larger one) and Kidani Village. These resorts are our favorite and IMO offer the best theming out of all the resorts. You could spend an afternoon there getting lunch, drinks and checking out all the African art displays. Also the savanna's of course!
Last couple resort hopping ideas would be the new Riviera which will be open when you arrive. We can't wait to check this out when we go in Feb 2020 as well. And the LAST recommendation is California Grill at the Complementary resort. This requires reservation for dining in most cases, but if you don't have strict plans, you could go the elevator check in area and ask if there is room at the lounge as this is first come first server. It has the same menu and while up there, you can check out the observatory deck overlooking Magic Kingdom. Some of the best views on property!! Especially at sunset. If you're up there when the fireworks start, you can watch them from the deck as well. They pump the music in - really fun experience!
I hope that gives you some good info! If you have any other questions, let me know.
