You can park at the MK and take the boat to WL. However doing this will take quite a bit of time. You have to park at the TTC, ride the monorail or ferry to the MK, then catch the boat to WL. It might be hard to make an 8:45 reservation. If you are staying onsite, taking the bus to the MK will be easier because it drops right at the entrance to the park near where the boat dock is. The monorail and ferry can get pretty crowded in the morning causing you to have to wait. If you are going to park at the TTC you need to give yourself plenty of time to make all of the transfers. It's doable. Have fun!!!