Re: This nearly happened in 2012
Its not even close to wildly overstated.
The power grid in the US has something like 5% redundancy, and the largest transformers have no backups or spares whatsoever. These are transformers that are not only built overseas, but they also have lead times of between a year an 18 months. Just a handful of these keep North America up and running.
What are the odds of multiple utilities going bankrupt and not being there to pay for or install said monster transformer by the time it has been manufactured?
From there it probably goes to shit a whole lot faster than 18 months anyways. Bronze age is probably optimistic.