History seems to present the popular understanding of the doctrine as gospel. We launch, then they launch (or vice versa), and the entire world enters a period of nuclear winter. The vast majority of earth's human population dies, etc...

Is this really what a bilateral attack would have meant? Was that, historically, the genuine thought of policy makers? Or was the idea something more like, "every US and Soviet city over x-population would be destroyed, a lot of people would die, but the world would go on. Both countries would lose their positions as superpowers"?

For instance, could a Kansas farmer with sufficient land for diverse crops, and water access, have hypothetically been able to survive and provide for his family after a nuclear holocaust?