Winning isn't impossible, just difficult. Overall, it's relatively random if you'll spread. The main thing is to keep low visibility until you seed most countries, especially the isolated ones. This means immediately after starting selling all your symptoms. You also want to buy into first level resistances so you can spread more easily but not too quickly, as that will set off red flags fast. After that, just give it time, let things progress and slowly spread. Once you have a good spread, start increasing your transmission an resistances so you can jump through the populations.
As you can see on the last page, you can start in Madagascar, which is infamous for being the most difficult to infect, as it only has one entrance - the port. Once ports close, it is clean. But do not forget there are other countries with only 2 or so entrances which can do the same. Greenland, Cuba, Japan, etc. included.
