Obviously this war is already making things more shitty for all Russians. 2 million people in Crimea in panic because it's hard to get out without fuel. No electricity, no fuel, no Internet, and food is rationed.
The fuel shortage is now a problem for all regions of Russia, and fuel is rationed by federal decree.
Siberia has the advantage that Ukraine has very few drones with long enough range to hit them. But yes most of the eastern Russian federation depend on the west economically and probably also for food. But many Russians in those eastern parts have already moved back west, resulting in for instance mining cities that are empty. Some are populated with Chinese and North Korean workers, to continue mining, because the Russians are moving away.