On my first visit to London, 6 years ago, Sir William invited me to lunch at his home, which given we had only communicated via WikiTree, was very kind of him. I also met his wife and two young sons. Even then he was having good days and bad days, but that didn't diminish his abiding interest in genealogy and family history.
I was planning to get back to London last year, and hopefully to renew the acquaintance in person, but sadly world events intervened.
My condolences to his family.