Where? I live in an very remote part of Northern Minnesota. Even so, worst case ambulance time to most people in my area would be 15-20 mins.
I would argue that an incredibly small portion of the US population lives >1hr from an ambulance or first responder.
http://www.flexmonitoring.org/wp-content/uploads/2018/01/CAH...
It doesn't show larger hospitals, so it is hard to directly answer the question about access to emergency care, but it shows that there is quite wide geographic coverage. The map in this article shows that the gaps are just where you would expect, in the extraordinarily rural west:
https://www.cnn.com/2017/08/03/health/hospital-deserts/index...
And that’s a medically meaningful difference. 20m response time, 45m to the hospital, you’re still in the time window for critical therapies for heart attacks and strokes. Several hours response time, you’re not. I mean to say, I’m not nitpicking: the difference between your scenario and what the previous poster asserts is large and medically meaningful.