Harsh winters are part of the risk you take if you invade Russia. I'm sure both the Germans and the French had a sense of that.
Hitler's operation Barbarosa, launched in Late Spring was planned to last approximately 5-6 weeks, The goal breaking Russian defenses, ability to rebuild and take Moscow. While the Germans took vast areas of land the main goals were unsuccessful in their timing, while the Germans did have some equipment able to operate in -20F degree or colder climates the vast amount of German mech units actually froze (grease), unable to move, in addition the German soldiers were inadequately equipped for the extreme cold. Unable to resupply both sides ended in a frozen stalemate, while huge casualties mounted on both sides. I don't believe that they will ever be able to put an exact number, or close approximation, to the death toll incurred on the Russian front. Over the centuries many conquests of Russia failed in the winter, Hitler's was no exception.
Russia alone couldn't have done anything. They didn't have guns, ammo, transportation or even enough food - that was all supplied mostly by the US and partly by UK. Just look what an ass whooping they took from Finland even when they had all the numbers on their side. Anyway, the Jews have brainwashed the rest of the world to thinking Hitler and Hitler's Germany had almost supernatural powers (which it didn't).