Ukraine has been consistent in what it considers the win condition. Russia leaves and returns to the pre-2014 borders.

I'd argue that is relatively tame. If the US was invaded from the Southwest, we wouldn't stop until we were dictating terms in Mexico City.

Now, whether or not Ukraine's win condition is achievable is a different question that appears to hinge almost entirely on the individual's priors about who would be the "better" victor. That's a whole different debate that involves more spreadsheets and maps than most of Twitter has any interest in, which is likely why it never seems to happen.