The Magic Kingdom fireworks are the same on the 30th and 31st. We went to MK on the 30th and Epcot on the 31st. NYE is the busiest day of the year, and there's a lot more room at Epcot. That said, CM's were directing traffic in the park all day and the crowds never seemed that bad. We left Epcot after the fireworks, from the UK pavilion, using the backstage walkways to get back to the monorail, and made it back to our room at Bay Lake in less than 30 minutes.