Bus. Check with hotel when you get there for earliest bus over -- they have a bus that runs for people going to an early pre-park opening character breakfast. Busses are not unreliable. However, many often believe they can get a later bus than they actually need. You need one that leaves no later than about 7:45. You won't be able to do the trek through Epcot to the monorail. The boat goes to the International Gateway entrance near England in World Showcase. You can actually walk from BWV to that entrance faster than the boat (about 8 minute walk). Nevertheless, if Epcot opens at 9, you won't be able to get through Epcot to the monorail at the front entrance until 9. Even if it has early entry and opens at 8 you won't be able to walk through until 8 and you likely won't get to the restaurant at MK until 8:45 or later.