No easy task! Fins speak excellent English and I've heard that in university if there is a non-Finnish speaker, they will simply conduct the class in English. They think they have a secret language, though, so if you're non-white you can scare them once you know some Finnish.
How your HK wife will survive a Finnish winter for five years... good luck with that! (But apparently they just inexpensively heat their flats through a system connected to their industrial areas?)
It's good to know others are in this boat. Since I'm married to an EU citizen, I will try that route, but it isn't easy and looks to be a commitment. Then, like you say @MRChips I will have "freedom" to move around.
Covid19 hasn't helped getting this sorted though with consulates closed, so I am unsure how or when we'll be prepared to leave HK and head to the EU when the time comes. We wanted to have our ducks lined up to be ready to go, but that isn't happening.
My wife misses Scandinavia... she's been through 3 Scandinavian winters including an especially hard one in Sweden where we were stuck at home for a few weeks...
We've started looking at Finish online... it's not too bad... certainly easier than Cantonese, and there are a tonne of free resources... also, it's possible to opt for Swedish on the language test in Finland and I've already tried it and I could probably pass that now... anyway, the goal is worth it!
Where are you going?
I'm a bit fatigued with living in a country where I don't speak the local language and having to start from scratch. But for the freedom it entails it is worth it.
Swedish will be easier than Finnish, as its a Germanic language.