Hi Pudds
Are you absolutely committed to staying in your house as long as possible no matter what?
If you are, that's perfectly understandable.
However, I have a relative that was in a similar situation to yourself up to a few years ago. She sold up and moved into a modern apartment complex within a couple of miles from her house. Just a regular apartment development - not particularly developed for retirees.
Best decision she ever made - according to herself. Secure, cosy apartment and no more worrying about the garden or a leaky roof. The move also freed up a few bob but that wasn't the main driver.
Not for everybody perhaps but it might be worth thinking about as a possible option.
As for what happens to your assets after your gone - well, that's entirely up to you. Any good solicitor will draw up a will to reflect your intentions.