Ask Lemmygrad

I expect Russia will annex most of Ukraine except the western territories where most nationalists are. Interestingly enough, we may see Hungary, Poland, and Romania jump on the annexation bandwagon as well at that point. All of them have been making noises at one time or another, and if it starts looking like Ukraine is falling over, they might decide to be opportunistic.

Best case scenario for Ukraine at this point is that it's going to be a nonfunctional rump state. Russia already annexed a lot of industrial and agricultural territory, and Putin just said that Russia will need a buffer to protect against long range NATO missiles. This implies that Russia is planning to turn a few hundred kilometres into a buffer zone. I doubt Putin would be publicly stating this if the decision wasn't already made.