I thought folks might be interested in a report generated in December, 2018 by the President’s National Infrastructure Advisory Council. The report can be found here:
https://www.dhs.gov/sites/default/files/publications/NIAC%20Catastrophic%20Power%20Outage%20Study_FINAL.pdf The document seems to be most interested in survival of government. To me, the most interesting part was Appendix H - References, which has many links to explore and to examine. At this point, it doesn't look like the government is prepared for such an extensive event.