All advanced economies are built to withstand energy droughts by having a) a mix of generation technologies and b) excess capacity. That is why Japan was able to cope with the closure of almost all its nuclear capacity and the US has been able to cope with a rapid rise in gas prices and France up to 1/3rd of its nuclear capacity offline over winter.

The US thermal fleet has some 900 GW of capacity to cope with peak thermal demand of  550 GW and average demand of 370 GW. Even if you allowed that peaking plants were expected to have low utilisation there was always enough CC gas, coal and nuclear to provide 40-50% more annual demand than they did provide. 

While nuclear does not provide a large share of Texas energy it will be useful in prolonged droughts. But Texas can get by quite well with wind and solar capacity designed to deliver 150-160% of annual demand supplemented by waste to energy, nuclear and some geo-thermal. It will still need storage probably equivalent to about a peak days demand or 20% of two weeks demand, but a substantial fraction of that will come from thermal storage as ice or hot water, vehicle batteries and even customer storage so at best (worst?) grid battery storage might provide 20-35% of required storage and very little of that will be Lithium /metal batteries. There would also be a substantial saving in energy costs, if fast start FF generators were allowed to provide a long term average of 5% of energy. The emissions from these plants could easily be offset by reforestation and regenerative agriculture