We will see.
Ukraine will not be allowed to join NATO due to disputed territories anyway.
As a Pole, after full blown invasion on Ukraine, I would support increase in military spending beyond current goal of 2.5%.
I also think that Sweden and Finland would join NATO relatively soon after invasion. After 2014 annexation of Crimea support for NATO grew there some 20-30%. Sweden is rattled enough to deploy symbolic military presence to Gotland. Joining NATO is part of political discussion in Finland, but they are on the edge.
Russia would only lose on war with Ukraine.