Even in that world, you'd still want a way to manage the load through the night so that you don't have all the chargers clicking on at 11pm and then when the cars are full have a few hours later, demand craters until morning.
With renewables the incentives for load management become even higher (per this article). The real next step after second-by-second billing would be setting up chargers with backfeeding capabilities/policies, so that you have an arrangement with your employer to charge your car at work on cheap daytime solar power, sell it back into the grid during the evening rush, then charge up again on overnight base load. Most EV batteries are way overspecced for what people need in daily use, so as long as you have a special "charge me to full and stay there" mode you can switch into, there'd be no reason (other than a bit of wear and tear) not to cycle your battery like this.
I think your household electricity prices just need to reflect real market prices. For example there were times in germany this year, with negative power prices, because the wind was blowing strong and all the wind plants generating more than anyone needed.
But for me as a customer, the price was as high as allways.
But if customers could react to that (automatically), you could have all sorts of jobs waiting for it. Bitcoin mining, dryer, charging batteries, freezer full power ... would be good for the grid, too, to balance it.
With renewables the incentives for load management become even higher (per this article). The real next step after second-by-second billing would be setting up chargers with backfeeding capabilities/policies, so that you have an arrangement with your employer to charge your car at work on cheap daytime solar power, sell it back into the grid during the evening rush, then charge up again on overnight base load. Most EV batteries are way overspecced for what people need in daily use, so as long as you have a special "charge me to full and stay there" mode you can switch into, there'd be no reason (other than a bit of wear and tear) not to cycle your battery like this.