I have a friend who has ridden from HB to Vegas. It is about a 350 mile ride. Checked Strava, I don’t think he was trying it again.
In the past, I’ve done multiple Davis Doubles and Markleeville Death Rides. My last hooray was the Seattle to Portland, which I was unable to finish due to a hip problem. Was in a small bike shop team, and we used to burn the Davis Double in just over 13 hours.