Both solar and wind were down. Wind turbines in Texas aren't weatherproofed either (cost) and it was generally dark and overcast. This didn't really matter since wind generation is a pretty small percentage of the grid and it was mostly gas generators (companies that produce natural gas for use in generation) that were the issue, but "more solar and wind" would have done nothing.

The correct answer seems to have been forcing the gas generators to winterize.

I don't think that'd help. There were a bunch of articles about how renewable power wasn't to blame and Texas politicians were lying by blaming it, but if you check the actual details the whole justification for that was that everyone knew solar and wind were fundamentally unable to keep the Texas grid supplied with electricty during winter due to low output and so the grid wasn't expecting to rely on them. That is, the argument isn't that they handled extreme winter weather well, it's that even in normal winters they're not useful.

Texas has huge and growing wind and solar resources. The entire west half of the state is windy desert. At one point you couldn't drive across I-40 without passing a 100-meter turbine blade convoy every few minutes. It's true that they can't supply the needs of the entire state yet, but wind power is hugely effective in the winter—provided you budget for cold-weather reliability.

It's very possible that in a competently run system, where both renewables and fossil fuels were properly hardened, wind would have meant the difference between blackouts and getting by.