You are seriously deluded if you think there is any chance of this happening.
A well supplied Ukraine may be able to eventually force a peace settlement or some form of Russian withdrawal, so yes a defeat for Russia but will they be buried once and for all, no they will merely have a bloody nose, similar to America in Vietnam and Afganistan, ultimately these defeats didn't matter a jot to the US in the general scheme of things.
Whether we like it or not Russia is here to stay be that in a more weakened state or not.
Sanctions you say, well after German et al exports have gone up by hundreds of per cent to the Stans its pretty obvious due to this back door, sanctions are having next to no effect.
While this is not my wish, I think the best Ukraine can hope for is Russia keeps the regions currently annexed and tbh it won't be too difficult to do that, as they all have a majority of Russian leaning citizens living there, remember Ukraine was at war with these regions for 7/8 years and got nowhere before the full scale invasion by Putin.