I seem to recall rolling black outs on Texas a few years ago during a cold snap. The weather system idled many of the windmills which provide a significant portion of electric power in Texas and two fossil fuel plants were down for maintenance. The cold conditions increased demand for electricity and there was no backup capacity available. Texas power authorities were even begging Mexico for electricity.
They’ve had rolling blackouts during a few really bad summers and winters, but have been working to improve it over time, and they’ve got the data they need to judge the demand. The most they ever used at once was something like 70,000 MW back in August of last year.
During the Superbowl at Jerryworld, there was a major ice storm coupled with electrical shortages. The utilities cut off power to homes, hospitals, and nursing homes to make sure the stadium had enough power to be comfortable. That’s probably the one you were thinking of.
Along about the same time, there were summer shortages with rolling blackouts. It was part of the squeeze to force the smart meter program on the public, and they ended the shortages when they got all of that approved and underway.