If this war goes on for several months, what I see is that Russia neither has the economic or manufacturing infrastructure to continue to be a viable force. In short, if we, the rest of the major players in the world, keep supplying Ukraine with the tools it needs to continue to keep pressing the Russian force, while we penalize Russia, Russia will simply begin to implode. We will bleed Russia dry of every military and government ability, except nuclear.
Like WWII, Germany simply didn't have the infrastructure or resources to win a longterm war against the rest of the world. Russia, because it has depleted its population of the ability to make anything but war, will, in the long run, start to collapse.
The only thing that makes Russia a major player on the world stage is its nuclear capacity.
This brings up some very frightening concerns.
What will Putin do if he has little left but bombs?
What will the Russian people do when Putin has bombed Ukraine into Russia's economic poverty and more?
IMHO, this is going to get a lot more scary for us all!