You can't just buy a house with a suitcase full of cash these days, it's not possible. The gov will be asking where that money came from, to prevent money laundering and to ensure it's not proceeds of crime. Whether not you agree with that, this is the situation.
The idea that somehow they'll let you buy something with Bitcoin without requiring the same level of disclosure is a complete fantasy.
I'm sure it's possible, although almost certainly very much not really liked by your solicitor!