If by win you mean go back to the pre-war state with their full territory and join NATO, I don’t think that’s happening sadly. Russia invaded to counter NATO expansion (that’s also why they invaded Crimea too). They’re not going to give any territory back unless Ukraine gets out of NATO and pulls away from the US.
Bingo! For Ukraine to win they need to surrender, they will never gain back the lost territory.
I think Russia would actually be willing give back the territory if Ukraine pulled away from the West and NATO. Their main priority is they don’t want a Western-aligned country on their doorstep. The problem is, most Ukrainians want their country to be Western-aligned.
This whole situation is a disaster.
Ukraine was fine being neutral until the west started propaganda in their country, literally they merged all news to make a one state media, is that democratic? Yes, Russia will most likely give back some territory (definitely not Donetsk for sure as they do not want to be with Ukraine). But then again, Russia gave up tons of territory as long as they stayed a buffer, and they didnt stay a buffer.