You sure about that? I don't think older homes were better insulated, or insulated at all.

I would assume that historically, cold snaps like the ones resulting in the Texas 2011/2021 blackouts were far less common.

To that point, an article [0] published shortly after indicates that 61% of all homes in Texas used electrical heating rather than Natural Gas. While -yes-, you still typically need electricity to run a gas heater, the grid demands are certainly much lower compared to an electric heater.

[0] - https://ajot.com/news/texas-uses-natural-gas-for-electricity...