do the math. the only scenario where EVs suddenly overwhelm the grid is if everyone depletes their batteries and decides to charge all at once at the peak on a warm summer evening. this will never happen, because in the 10+ years between now and a truly huge number of EVs being on the road there are very simple adjustments to the cars and the grid which would stagger charging over the many off peak hours at night, in the morning, etc. people already do this because it’s stupid to pay peak energy prices to charge a car that you can charge at night, off peak.
there are 13 million households in California. 50 miles per household per day. (I’ve seen numbers as low as 30, this varies a lot but 50 is very conservative.) 650 million miles a day. .25kwh/mile. 160 million kWh per day, or 160 gWh. California generates more than that much every day today (+/- 185 gWh) from renewables in-state alone. the state can and easily will build that much more in the next couple decades.
the bigger impact is actually the switch to all electric buildings, which is already here for many new buildings. it will take much longer transition since buildings last so much longer than cars, but it’s about an order of magnitude bigger impact.