Here is the fact, and there are no such thing called alternative facts...
Never pay off your 30 yr fixed rate mortage on your primary home (several keywords here, I am assuming they are all true for you, even if you live in Finland). Why? because it is a good debt. It is probably at an interest rate of 5% or less. Anything you do in the investing world will give you more than 5% return (not just crypto)
If you feel uncomfortable about holding a lot of crypto (and you should), you should sell a portion of it, and buy another house. Investment property. And put it for rent. Collect the income.
Soon you will have a portfolio of houses, the rental income from which will pay for the mortgage of your primary residence (the magic number is usually 4, here in the US, which offsets the mortgage payment of primary).
Once you have done that, you are golden. Live happily ever after.
RE: Wen Sell