The Houston Chornicle writes:
Texas has the only American electricity grid with no rules for resiliency. Instead, the GOP majority argued that a system that pays higher prices when demand goes up would incentivize generators to make sure their systems work during extreme weather. [...]
Another polar vortex almost exactly 10 years ago triggered blackouts. [...] The Legislature appointed another investigative committee in 2012 but ignored the advice to set resiliency standards. Instead, lawmakers concluded Texas electricity customers should pay generators even higher prices. The state Public Utility Commission raised the maximum payment per megawatt hour from $4,500 to $9,000 in a market that normally pays $25. [...]
The Texas Blackout proved that even $9,000 an hour [i.e. per MWh] was not enough to convince companies to weatherize properly. [...]
All other grids are regulated by the Federal Energy Regulatory Commission, which requires weatherized pipelines and equipment.
It's easy to confirm from (many) other sources (e.g. Reuters citing the U.S. Energy Information Administration) that grids in other US states are subject to FERC while Texas' isn't, but I'm having trouble finding the FERC regulations that dictate "weatherized pipelines and equipment". This might be because FERC actually delegates its reliability angle to the NERC (seemingly under the EPAct of 2005). So does FERC (or NERC) mandate such "weatherized pipelines and equipment"?
Section 215 of the Federal Power Act requires the Electric Reliability Organization to develop mandatory and enforceable Reliability Standards, which are subject to Federal Energy Regulatory Commission (Commission) review and approval. Commission-approved Reliability Standards become mandatory and enforceable in the U.S. according to the Implementation Plan associated with the Reliability Standard, as approved by the Commission.
But from that page it's not clear to me which of those (rather many) documents are about weatherizing.