Bogart doesn’t look very old to me. And he looks healthy. I have a rescue basset who’s deaf, dumb, and blind—about 15 years old—and I wouldn’t hesitate to take him with me if I was going over long-term. He may not see or hear, but he can smell, and he loves to go on long walks. His nose always tells him where he is.
I think the quarantine is still six months in England for pets.