Blackouts happen if the power lines themselves get damaged. But rationing and rolling blackouts due to insufficient capacity are basically unheard-of.

Rationing happens, but it only affects large industry etc who have contracted to the arrangement.

Which is what this scenario was.

I heard it happened in California.

"In August 2020, hundreds of thousands of Californians briefly lost power in rolling blackouts ..."

https://abcnews.go.com/US/california-blackouts-power-grid/st...

There are various ways to prepare for future potential badness. One solution embraced by Texas, amounts to "yolo", resulting in gas-fired plants being inoperable during the cold snap in Feb 2021[0] . A different solution, favored by many other locations across the globe including in Europe, is for there to be regulations set by the government, saying "you must perform this upgrade". While these regulations cannot alter the fundamental laws of physics, it is eminently possible to “winterize” various aspects of power generation and delivery systems through practices like insulating pipelines.

[0] https://www.texastribune.org/2021/02/17/texas-power-grid-fai...