No, all three grids US don't have the power to support most cars becoming electric atm. Heck, on the west coast they occasionally have controlled blackouts because there's not always enough power as it is. The Texas grid, while having some flaws, would probably be the most agile to be modified on a dime. The US east and west grid need to deal with the US Feds, US States, Canadian Feds, and Canadian provinces and would probably take more time to modernize.

Edit: Copying my below reply for clearification Maybe I should have worded it different. Once in a while places with high population centers have relative power shortages. According to that article the last California controlled blackout due to power shortages was 2022, so it's not like we're talking third world regular brownouts or anything.

I just meant it in the way that the power grid is old and was built during a time when we used less power, and while it generally works it's already at capacity and increasing capacity would require a lot of investment and cooperation.

In this particular case, a small grid controlled by one bureaucratic entity, as apposed to many bureaucratic entities across multiple countries, might be more easily modified. But, to my knowledge, none of them could support a sudden increase in power needs as they are currently (see the several big Texas blackouts, or the above article).