Like you, I have been listening to and enjoying the War Doctor series. I knew that he had been ill, and I think that fans are lucky to have that little gap filled in. He is terrific in them as the world weary Doctor who isn’t the Doctor any more.
I know that he wasn’t a huge science fiction fan, but he committed totally to anything he was doing irrespective of whether it was Doctor Who or The Field or Elephant Man or whatever.
Edit: A link for anyone who isn’t aware of Big Finish Productions or their Doctor Who Audios.