Ironically there are two very important things you are missing here:

1. Ukraine did not invade Russia like France and Nazi Germany, it was the other way around. There is no Ukrainian soldier on Russian soil.
2. To return to Nazi Germany, the Ukrainians themselves were among the Red Army during those winters of 1941 and 1942 which defeated the Nazis.
3. In a Russian civil war (see the White Russian counterrevolution), the winter is irrelevant. Ukraine vs Russia is just an extension of an imperial Russian civil war.