The message from Tesla cited different peak hours than ERCOT, as Electrek shows, but it was essentially the same period of time. Tesla’s prompt said:

A heat wave is expected to impact the grid in Texas over the next few days. The grid operator recommends to avoid charging during peak hours between 3pm and 8pm, if possible, to help statewide efforts to manage demand.

ERCOT asked businesses and residents to save energy from 2-8pm, then braced for the power demand. And the power grid scraped by this time, managing to prevent major outages thanks to voluntary cutbacks in power use, according to Reuters. Industrial users were among those volunteers that helped the power grid avoid collapse; even bitcoin and other crypto miners pitched in.