Let's be sure to qualify "work perfectly fine" to mean that they typically don't freeze up (heated blades, nacelle and housings). They can still be shutdown due to impending over-speed and don't produce when it isn't windy, which happens frequently during the summer months and cold snaps.
This is one of my go-to shots from the summer of 2019 (I track wind turbine output across Ontario):
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No amount of winter preparedness mitigates a lack of wind, and winter capacity, during a cold spell, can be similarly impacted as it is during a hot spell in the summer. During the most recent one, wind output in Ontario was below 200MW (of 5,000) for several days.
Now, I will add that overall wind performance is better in Texas than it is in Ontario, but we are still talking of a total output profile of ~1,000MW of 28,000MW at its lowest during the events of the 15th even if they had been fitted with the cold weather package.