More and more I think Cuba is likely if they scale it down enough, or at least the shoreline. The gaping hole to enter Havana is a dead giveaway of the scaling down, it's there in the other map and real life, but it is much smaller. With all those locations around it (Matanzas, Castille de Jagua, Cape Bonavista, Portillo) it sounds possible. Juventad Island has been clearly made bigger, while Cayman IslandS has become Cayman Island. I think it's possible for them to make this all explorable with proper scaling and making that pretty much a Frontier-size area just that being able to trick us because of the amount of water.