Multiple people here have reported that their car has allowed 15 minutes or more without having to touch the wheel. If each warning reset that timer, by design or bug, then you could easily travel 50 miles plus.

Plus, I'm almost certain that Tesla's goal with the system isn't to "have an autonomous system that you have to interact with steadily", hence the 15 minute warning in the first place. They have perverse incentives - to allow it in the first place implies reliability that may or may not be there.

Meh.. I assumed it was a buggy case that allowed more than an hour of hands-off time.

Why would you need "more than an hour" to do 50 miles? Especially where you'd expect autopilot to be most used (highways)? 'round here it's about 40mn highway, and barely an hour (give or take) inter-city, and that's driving at posted speeds which people don't necessarily do (and I expect Tesla does not enforce)