TLDR version: Finland proves you can exercise deterrence against a numbers-bully. No capitulation on your sovereignty required.
Wordy version:
Russia doesn't have any incentive to negotiate back to pre-Donbas annexation, so that's not gonna happen. They'll keep throwing their expendables at the grinder, as is the way of that ghastly Russian so-called Federation, which in all honesty has always been a shaky held one at the point of many rusty, but outnumbering guns.
Ukraine could capitulate even more territory, but all it buys them is time for the next assault. Ivan will come for them again.
The Ukranians need to read the Finnish playbook more deeply. Finland almost went the way of Ukraine historically, but managed to reach the lifeboat with NATO membership and more importantly, a very strong homeland-defense prepositioning policy. Finland is the mother of all, living-defensive line. Heck even shouldering up with the actual Nazis was necessary in order to bloody up the bear's nose, no fucks given by Finland. Life is grey, at least for us Realists.
Fact is if Lenin hadn't been so easy on Finland the first time (1910s) they broke away from Russia, theirs would be a similar story as today's Ukraine. So people need to give Ukraine a bit more benefit here on the whole capitulation front. Remember, population wise, Finland is a piddly tiny country compared to Ukraine, yet the deterrence outcomes between the two are stark. Yes, Ukraine got saddled with the Soviet Union proper after WWII, that's of course the biggest historical obstacle.
Let's also remember that Finland too, gave up some land. But then they effected a brilliant homeland deterrence policy for a Country of such small size. Ukraine needs to go full Finn once any cease fire is afforded to it. The Finns don't forget the 11% they gave up to this day, and neither should Ukraine.