It is more than that. Germany depends on Russia for a large amount of its coal and oil as well and their economy is driven by trade with exports and imports each amounting to roughly half the country's GDP. A loss of Russian resources would eventually cripple their industry and deprive them of a major source of economic strength. At the same time their businesses are the ones most exposed to Russia.
One really has to consider how interconnected the various European economies are in order to understand exactly how destructive this situation would be for the EU. I don't think analysts talking about the problems from a cut-off are really putting much thought into their rose-colored views. As I have noted elsewhere, the Baltic states and Finland get a large portion of their electricity directly from Russia, in addition to their various hydrocarbon fuels. On top of that, the Baltic states depend heavily on trade with Russia, trade amongst each other, and trade with Finland.
The immediate loss of electricity, natural resources, and trade from Russia would be devastating beyond anything that would affect Russia in the short-term. What makes this a disaster in the making is the exposure of the Scandinavian banking system to such a collapse of those economies.
According to the IMF, a major loss on banking assets in Finland and the Baltic states would cause Swedish banks to incur significant losses, forcing deleveraging equivalent to several points of Sweden's GDP. Denmark's banking system also has
huge exposure to Finland and the Baltics. Norway has exposure to those states as well, but their exposure to the Swedish banking system is the real risk at that point. Its largest bank has some
exposure to the Baltic states and the other Nordic countries, but the Norwegian banking system also includes a number of Swedish banks. One bank with
nearly half of Finland's banking market is
considered "too big to fail" in Norway due to the size of local subsidiary.
Basically, a collapse of the Finnish and Baltic economies is liable to cause a severe financial crisis all over the Nordic region, which would cause serious systemic risks all over Europe. At the same time Southeastern Europe would be experiencing price hikes and Bulgaria would be facing severe pressure due to the near total dependency on Russian oil and gas, not to mention refined petroleum products, together with their lack of sufficient storage to meet the loss. Austria would be undergoing serious pressure from the outset due to Raiffeisen bank having
an eighth of its assets in Russia, in addition to exposure in Ukraine and Bulgaria.
For Europe, their only hope would be that Russia capitulates within the first three months. That would be their only saving grace. If Russia holds out that long they gain the upper hand
.......
After three months, Brussels will have little choice but to cave. Otherwise Eastern Europe will see its entire economy shutdown in the face of fuel droughts and blackouts, which will quickly bring down Austria and Italy as well due to their own dependency and their outsized banking exposure to Eastern Europe. By then, the system will be too far gone for anyone to save. In Europe's current economic and political state, not getting Russia to concede within the first few months means facing total disintegration. The problem is that, as I noted, Russia has the financial resources and political wherewithal to plug the gap enough to avoid any massive downturn for months. However, no amount of money can plug an energy gap.