Under the circumstances, I'd accept just slowly rolling to a stop with the hazard lights on. People behind the car will hate it, but probably no one will die.

Sadly, I can still imagine someone crashing into a static car on the highway. I can imagine normal-speed continuation, mid-lane stopping, and attempting to navigate to the side of the road all seem to have some pretty heavy risks. I do wonder if a low-speed continuation would be in any way suitable.

A "safe stop on the high way" means the side of the road in normal everyday context. That would be appropriate here, no? Highway patrol would check out the car pretty quickly.

Getting to the side of the road seems like it could be pretty risky for current autopilots, though perhaps things are further ahead than I know.