Its truly a tragedy, though one playing out all over the nation, not just in TX where the news coverage is heaviest. I moved from there about 18 months ago, still in contact with friends in Austin and parts of east TX. Its bad. Had they not begun upgrades on the system (and made a lot of them) after 2001, it would be MUCH worse.
Depending upon source, TX lost about 46 MW of power generation during the peak of the outages. That's more than the TOTAL summer net generation capacity of every state in the union, except CA, FL, and PA. PA, for what its worth, has a net summer generation capacity of 47 MW. NY only 41. FL is 60.5 and California 75MW.
TX summer net is 125MW - they lost roughly 40% of their theoretical maximum capacity, and had never previously needed more than 69MW at peak.
As context to put things in better perspective.