Leonardo da Vinci would be my first choice. I’d love for him to witness just how forward-thinking he was. Imagine his delight when he sees that humans can fly. J R R Tolkien would be my second choice because I really admire his world-building. Jane Austen, because I love her sassy female leads and Mr Darcy!
It’s very intermittent. I have chronic pain syndromes, which include chronic fatigue and problems with memory, and joint problems which add to the pain. So I write when I’m able. Writing does help me to escape from my problems, but sometimes it just doesn’t happen. So it’s all a little haphazard.