We've stayed at BWV 6 times and have never had to wait until 4 pm to get our room. The last time we were there it was post-cruise and we arrived at the resort around 10:30 am and our room was ready (We were shocked, quite honestly). Even last year when we checked in on Christmas day our room was ready when we arrived around 3 pm. That being said, it's definitely not guaranteed that your room will be ready. We've had experiences at other resorts with our room not being ready at check-in time. It's really a "day-of" situation. If you don't have any other requests, you may want to mark on the online check-in page that you would like a room early (that will superseded other requests). Or, just be prepared to not have a room until you get back from MK later in the evening. You could pack some things to freshen up in in a carry-on, use the rest room, relax in the lobby or on the lobby porch and leave any day bags with Bell Services.