I’m not going to pretend I’m knowledgeable on the subject but opinions I think are well reasoned are contained in this article. (March 2022) Just linking it for the purposes of discussion.

Also this one (May 2023):

Mearsheimer expects that Russia, which already has incorporated four Ukrainian oblast plus Crimea, will take another four oblast from Ukraine. (I predicted this on February 24 2022, the day the war began. Those eight oblast plus Crimea are historically Russian land inhabited by Russian people. During the last thirty years they have consistently voted for pro-Russian candidates while the people in west Ukraine consistently opted for anti-Russian candidates.) Ukraine will end up as a dysfunctional (and poor) rump state.

And finally: (December 2023)

There will be no terror for Ukraine, just the loss of the ethnic Russian people, industries and land the communist - Lenin, Stalin and Khrushchev - had for whatever reasons attached to it. The rest of it will be a smaller, more poor and purely agricultural rump state without access to the sea. This was obvious from the very beginning to anyone with a clear view of the balance of the forces involved in the war.

I know this is all the same website, but it’s citing and aggregating different sources for its opinions. It’s also not at all Marxist analysis but it needn’t necessarily be for these immediate purposes.