Your guess is as good as mine where the final lines will be drawn. I think Kharkiv will be taken and kept by the Russians, Odessa is more of a question. Russia may calculate that leaving Odessa in Ukraine will help Russia in re-establishing diplomatic norms post-war. Taking Odessa and leaving Rump Ukraine landlocked would be seen as pretty scorched-earth. But you cannot discount Russian anger about the 2014 Maidan Coup/Revolution, and especially the arson massacre of Russians in the trade union building. So who knows.
