I'd say a better title for this article/graph would be "How would electric cars affect CO2 output in European countries?" or something along that line.

There's far more to a specific car being a good idea considering the differences between EVs and ICEVs (but of course the needs vary inside countries as well). However, an electric car is much less attractive in a land of long distances where you often need to keep the batteries pre-heated to provide even reasonable range (and even keep your warranty!) – even if the country's electricity production is not dominated by fossil fuels.