I've been playing for a couple weeks now. Every time I played, I just ran out of turns. I would declare independence and kill all of the REF that showed up on shore, but in the end, I never had enough time.
The two times that I have won, I've done by building a big empire and pumping out the ships. Killing the King's navy isn't that hard if you start the RWI with enough boats. Once he's out of ships, the game is over.
After the MOW dumps his people onto the ground, they like to hang out for a few turns around your cities before they return to Europe. I keep three SOLs in a city likely to be attached. When the MOW shows up, I attack it from inside the city with my SOL. I will usually lose one or two SOLs, but the third will always win. When you kill a MOW for the first time, your SOL gets two upgrades. Killing another will usually give you another. I give them Skirmish I, Skirmish II, and Veteran. With this awesome ship, you can attack with the MOW, likely win or escape, and you can finish off the MOW with a frigate.