We did the same thing last week. Left the MK around 3:40 ... walked to the boat dock and luckily there was a ferry waiting to go to FW. We were behind a long line of people but managed to get on board as they allow standing on the boat. The boat ride took about 10 mts. to get to WL, where it stopped first. Then a few more minutes to FW. We ended up getting there around 4:15, which was more than enough time before the show. We walked around and visited the general store and horse stable before they let everyone enter the HDD, which was right at 5:00. We had a blast; you'll love it!