Nineteen Eighty-Four is not exactly sunshine and roses. It is forgivable to surmise the author would not be a happy camper. I was glad to know Orwell shared some happiness with his tyke in his final years.
(On the other hand, the great spreader of sweetness and light, P.G. Wodehouse, who I also like, seems to have been pretty quiet and unadventurous in person.)
I found the article about Orwell's son a good read. Not sure why the author assumes having Orwell as a father would be "pretty grim", though.