I know people who hunt them and have killed them over 40 lbs! Biggest I have ever seen a picture of (verified, not photoshop) was right at 50lbs.
I have seen video of a large bobcat taking down a yearling deer (deer had no spots - probably about 40-45 lbs).
I thought I saw one recently, and I estimate about 70lbs (compared with my old hound, who is a little smaller but sturdier). Definitely 50+, probably not 80.
I have seen them before, and coyotes are plentiful, so I’m not surprised, but even to me this was a big cat.