What's the range of that pulse, and how does it relate to the field strength map seen on Wikipedia (https://commons.wikimedia.org/wiki/File:EMP_mechanism.png)?

Naively, this map makes me think that a single such EMP means enough electronics break that every major power plant or industrial plant is down and not recoverable for weeks.

The protection is provided by Digital Protection Relays (DPRs) which can be fried by the E1 pulse; then the E3 pulse arrives.