When, not if. The war is unwinnable for them, because the strategy of its artificial lengthening without any realistic goals, by means of kleptocratic military dictatorship, provides only one clear path: to destruction. Any ceasfire will lead to immediate collapse of Zelensky though, and that’s precisely why he cannot stop. ;)

However, ceasefire can be discussed in seriousness again as soon as Zelensky be ousted. I’d say he has no more than a year of life in reserve, in more senses than one. Maybe even less.