Finland has a very dangerous choice.
Either way, she is going to be in conflict with Russia soon, as Russia does not acknowledge it as a legitimate state but a breakaway province.
Same with the Baltic States, Poland, and probably part of Germany. Now, Russia knows it can’t digest all that, but Scandinavia joining NATO will lead to conflict.
The Soviet Union failed during the Winter War with Finland. The time for Finland to join NATO is now. The Russians are not capable of invading Finland at this moment.