The electical grid in Texas is optimized for the summer months when 95+ days are the norm. The Electric Reliability Council of Texas (ERCOT) is a consortiuum of electric generating companies who manage the distribution of power throughout most of the state. In order to keep utility costs lower for a pro business environment, power generation facilities are taken offline during the winter when low temperatures of a few days in the 20s is the norm. Maintenance is done, fuel stocks are depleted. It takes an effort to bring them back on line. It is not a flip of a switch.
The cold weather front which brought -2 degrees to the Dallas area, shattering the previous all-time record low of 8 set things in motion. Calls for additional electric power stretched the grid to the breaking point. Rolling blackouts were called for, but system failures caused whole swathes of area to fail. The initial assessment is that the grid was minutes from total failure - how close it was will be determined by investigations now starting. Back in 2011 there was another cold snap - not as extreme or extensive. Recommendations were made about ERCOT and its practices, but there would be a cost involved. Needless to say they were not implemented. There is great political pressure to keep energy costs low for pro-business reasons. A few wind turbines failed, but not enough to crash the system given the hundreds of acres of them there are in the western high plains.
With reduced electrical, heaters which might have helped keep natural gas wellheads warm and pumping failed. This reduced the available natural gas for alternative electical generation and/or home heating - gas heat & gas fire places.
Reduced electical also caused failures at water treatment plants; pump and valve failures. There may be water in the lake but you can't get it through the plant into the storage tank.
There are only something like 29 show plows in the whole of the north central Texas DOT. I think I read that there are 300 in the whole state. Typically when a storm hits one area, DOT can borrow resources from other regions. When the -2 degree event occured there were winter weather advisories for all 254 counties in Texas, all the way to the Rio Grande valley. Why invest in a snow plow if it is only used once a decade?
Construction practices have many water pipes run through outer walls of structures. Typical cold weather practice here is to drip your faucets mounted by exterior walls to keep the pipes from freezing, that and open the cabinet doors to allow the warmer room heat in to help too.
So now, colder than it has ever been before. No electric for heat. If your house is built for gas, no heat. Your dripping your water faucet has depleted the water system or your pipes have frozen & burst (or will burst when they thaw). Roads are covered with ice. There is a pandemic going on causing some people to refrain from going to disaster shelters, if they are open & they could get there.
No power in grocery stores - perishables get discarded. Runs on staples and bottled water. Trucks can't restock because they cant get there over the roads. Oh, and by the way, many local food banks have been running large food distribution events due to job losses from the pandemic. Food is already a concern in parts of the population
So what is going on in Texas? It is a cascade of problems and events; many known about for a decade or more, some unseen. I won't go deeper into the politics/politicians. They are part of the problem too.
For me in the Dallas/Ft Worth area, 4 to 6 inches of snow in the two storms. Didn't loose gas or electicity. Replaced my windows last winter and they performed well. Ran thermostat at 64 to 66. Brick construction with only kitchen & upstairs bathroom on exterior walls. Dripping & room heat worked well. We had a good supply in the pantry and have eaten well, but will need to go to the store in a day or two. I'm retired and don't need to go out. My wife is a nurse and her schedule is flexible. Fed the birds, watched it snow