I dont think whoever wrote this understands how power generation works. You don't make more power than what is being consumed. On days when wind and solar a putting out good amounts of power, they idle down the gas a coal plants to a lower load.
They can't make excess power, so none of it goes to waste.
Also, I work in the industry in plants around this area... They have been upgrading a lot of shit. And my base plant is actually part of a pilot program to fix a lot of the winter issues they had.
One of the plants I worked in down in that area is relatively new, and it was only engineered for temps at 15 degrees F. It got down to -15 and was fine, thankfully.