I'm a bit like Varian, for me I have the television on very low, just enough to have to concentrate.
When I'm at home, it's a dvd of Frasier, the same one every night, 4-6 episodes. If I wake up and realize I've missed one, I find it comforting to know that I Really have been asleep and can do it again. The majority of nights I'm asleep before the end of the dvd, often out cold until the alarm rings.
Good night, 7.5 hours, OK night 6.5-7 hours, bad night 5+ hours. For many years after chemo, I'd have been ecstatic to have had 5 hours.
(World Champion Sleeper until chemo 9 years ago.....)