Take comfort in the fact that it’s highly unlikely it would last that long. While a black start of the power grid is hard and long, for most areas it’s long on the scale of days, not months.
Low priority, read poor, places may be put for a weeks to a month or so, but the stores and cities probably won’t be. For all the author cites a vague cyberattack, nearly all of our core transmission infrastructure is primarily protected by dumb fuses and fail safe design.
The closest I can come up with for an attack that physically damages infrastructure would be some long running backdoor in a bunch of diffrent SCADA systems at various power plants being used to come up with specific lines of attack for each plant, and even that’s couldn’t get all of them. It’s also pretty unlikely, though admittedly not impossible.
If it makes you feel better, note that Ukraine has been dealing with constant cyber attacks on its grid by a nation state actor with a major cyber warfare program, as well as near constant missiles to anything on the grid that looks important or expensive, and has been able to by and large keep the core of the grid online, although admittedly it does have outside help in doing so.
While cyberattacks on SCADA systems can definitely be done, see stuxnet, they arn’t magic. Instead requireing specific exploits in specific versions of often not even internet connected software.
The grid isn’t all or nothing, so the remaining stations would be able to come back online and link back up in a few hours, and more and more customers would be brought online as generation capacity grew to match, prioritizing things like hospitals and shops.
All telecom stuff in the US designed for at least 72 hours without power, and a lot of it does have backup generators and plans to keep those fueled long term. Hospitals need to have a week of fuel on site, and again they have plans to get more in.
The reason why we don’t have a clear nationwide plan in case of cyberattack isn’t that no one’s thought of it, but rather that the reaction depends heavily on what plants are down and how long it will take to fix them, and we can’t know that in advance. Instead each local operation has its own maps, troubleshooting guides, and training on how to bring its parts back online. These people know how their shit works, what it does, and how to cobble together replacements for broken components.