It obviously depends a lot on how the war goes and if Putin manages to stay in power (and whenever his eventual successor would be one of his followers or someone with directly opposite views on the foreign politics in general).
I really don’t see any realistic scenario where this situation resolves without further violence. Ideally you’d have a proper lawful referendum at some point but it still won’t be fair as all of the sources of alternative political information are blocked by the Russian government and the people have been brainwashed by the Russian (and anti-Ukrainian) propaganda for the past 8 years.
But even if they weren’t, I can’t really remember the last time where a country willingly accepted independence of one of its states (and I’m talking about both Ukraine in 2014 and Russia in 2022 or further in the future). Possibly it would’ve happened in UK but the Scottish referendum didn’t go that way (although I’m really uninformed on the matter, just wanted to point that out before any of you guys go to correct me). I do believe, for example, that Crimea probably would’ve still voted to join Russia in 2014 if that referendum was done fair & square under the UN supervision, but we’ll never get to know now — and you can’t just roll back all that 8 years of Russia’s persistent attacks on Ukrainian sovereignty. And obviously the way it was done in reality makes the whole “referendum” thing null and void.
