Earlier quoted context omitted.
What is "proper winterizing" for a state where the 99th percentile design temperature is mostly 25-30ºF? Properly sized heating systems should run 24 hours a day when the temps are well below the design temp. If almost all of those systems are electric (because they are simple and cheap to install and don't get a ton of use), you get a lot of constant demand for electricity. Smart load-shedding (to dump large 240VAC…
as long as they're an independent grid, optimizing for the 99th percentile isn't really acceptable. that's only two nines. if you have a contingency plan for winter storms, then it makes sense to skip the winterization. but it appears their plan for a winter storm was just to fail.
It doesn’t mean you design the grid to only sustain the loads 99 percent of the time. This is going to turn out to be a grid implementation problem, not an insulation or a renewables problem.