House prices are massively inflated (2-10x depending on the location of the house). I remember people saying in 2007 (before the last housing crash) that a particular house was too expensive at $300k. This year, that house is valued at $650k and nobody says it's too expensive. People across the planet (US, China, Europe, Australia, etc) are irrationally optimistic about home prices and they will soon begin suffering greatly for their irrationality.

Because housing prices are about to decrease substantially; the crash will begin within the next 24 months. If I had a mortgage on a house, I would sell immediately. Waiting to sell would be dangerous, because timing the market is how you lose everything. (The market punishes arrogance.)

It doesn't matter what Bitcoin does, because the alternative is that you could lose your house in foreclosure. At least if Bitcoin goes down somewhat, you still have something to sell. Moreover, Bitcoin's track record is far better than houses, accounting for the ups and downs of both.

If you do sell your house, you have two options:

Getting wealth is hard work. Keep that wealth is hard work. Losing wealth is as easy as accidentally telling the government you are wealthy.