Do people with electric cars only charge once per week? I concede There could be some demand response if people could know that they can charge for less every Sunday night. But as you say when you are empty you are a price taker.

I live near Vancouver which features the most expensive gas in North America, and decent public transportation, and I believe traffic is the only thing that keeps people from driving more, not cost. So demand seems inflexible over the long term, and with electric cars I think you have even less flexibility to choose your time and place to charge, unless charging becomes ubiquitously available.

Tesla ranges (320+) are over 20 times the average commute (16 miles).

I think the more realistic scenario is that people charge less if the power is expensive, to full otherwise. Managed by a programmed policy.

Also, commute length will start trending down as we leave the cheap-gas phase of history behind - EVs are also too CO2 intensive to sustain the car based lifestyle.

Yes, many people with big-battery electric cars can charge less than daily.