Personally I’d buy myself a nice yacht and **** off round the world..
My advice to you however given your comment about retiring, I’d sell your current gaff as it is, since everyone wants to knock you down and or they’re looking for property they can do up and get the perceived benefits, you’d just lose what you invested in this current market.
So having sold it, take the money from the sale and your windfall and buy a decent new build which will be very heating efficient, then fill the roof with solar and chuck on a wind machine, or fit heat pumps and water collecting stuff or whatever other green stuff you can lay your hands on to get ‘off the grid’ thereby saving thousands paying to the power & utility companies.
Oh and hookers, though personally my plan is to fill the yacht with hookers that can cook = cookers one for each day of the week ‘cept sunday.