It is hard to believe that cold intake causes this massive startup problem. First, it is summer here in Finland and temperatures have been near 30 degrees celsius. Second, that king of problem would been there from the factory and I don't believe that car is designed the way that it would not start easy if it is cold.
I think that there is some kind of problem with carburetor, but I am not good with carbs so I have no idea what kind of problem it would be.
Or maybe spark is so weak that cold fuel/air mixture does not ignite. This is difficult to test also.