Quality heat pumps will extract heat from the air even below 0F, and they are more efficient than resistive heat (disclaimer: I have a high quality heat pump). It's not a silver bullet, but combined with weatherizing homes properly, it would've reduced peak demand on ERCOT (although ERCOT should probably have pressure applied on it to force natural gas generation and infrastructure to winterize so that this infrastructure can continue to operate during extended cold snaps, because it's clear in the decade(s) ERCOT has known this is an issue [1], they haven't done a damn thing to address the problem).

[1] https://www.houstonchronicle.com/business/energy/article/Tex... ("A federal report that summer recommended steps including installing heating elements around pipes and increasing the amount of reserve power available before storms, noting many of those same warnings were issued after similar blackouts 22 years earlier and had gone unheeded.")