The waiting is the hardest part...

[Bulby37]

The conventional wisdom is that Madagascar is best, mainly because you have a little more control over the transmission because there is no over land route. Greenland is a cold area, Australia has more scientists, and Madagascar just has less trading, so there is a better chance it won't spread until you are ready to. I don't think Greenland is a terrible idea though, because it is generally one of the last places I manage to infect. Best way to fix that? Pick Greenland as the starting zone! You just have to factor in the need for cold survivability earlier and watch your spread due to the close proximity to civilization.