I want to see electricity meters configurable with a "max I am happy to pay per day" setting. When that limit is near, they beep/alert you. When you hit the cap, they turn off the whole house.
You could adjust the limit as you please, with a default of perhaps $100 - but they spare you from million dollar bills, even with uncapped dynamic pricing.
If a reasonable number of these were deployed, the prices would never spike super high, because there would always be someone else willing to turn off their tumble dryer to save 50 bucks.