Edit: Here's a PDF of all the standards from NERC. Search "winter" or "ice" or even "cold" and you'll get zero hits.
https://www.nerc.com/pa/Stand/Reliability%20Standards%20Comp...
https://www.ferc.gov/legal/staff-reports/08-16-11-report.pdf
The very west (i.e. El Paso) and east parts (Beaumont) of Texas are not covered by the ERCOT grid, they invested heavily in weatherization after 2011, and neither of them are experiencing anything close to the catastrophe in the rest of Texas:
https://news.yahoo.com/parts-texas-not-ercot-power-080159059...
My family in the area lost power for more than a day. And as another anecdote, my friends in Lubbock (also not part of ERCOT) were powerless for two days.
I’m in Austin, and while things indeed seemed worse here than either Lubbock or Beaumont, they were still quite bad in those places, too.