I don't think it's likely. Finland was simply not that big of a prize once Soviets pushed the border far enough from Leningrad, so the amount of inconvenience required to change their plans was achievable for the Finns. Ukraine is a different matter, though, for both economic and cultural reasons. I could see Russia deciding that Western Ukraine isn't worth it, but that would still mean the loss of most of the country for the Ukrainians.

The other thing is that the invasion has already triggered those massive sanctions, and they aren't just going away even if Russia pulls out. If Russia does pull out, it'll have paid that price for no gains. So I think that they will keep pushing even if the military costs are higher than anticipated. Putin especially, since this entire escapade appears to be his pet project - the elites who are hit by the sanctions would have a great excuse to remove him.

So I do think that it will be occupation and guerrilla warfare for a while.