Well, the chargers won't be pulling 1MW continuously, so you can smooth this out by installing batteries with the chargers. The grid demand becomes a more constant trickle into the batteries co-located with the charger
the idea would be to slowly charge the capacitor to its capacity in the breaks between the charger being used. That way when you arrive at the charger, the capacitor would be fairly full and able to quickly transfer that energy to your car. The charger would then replenish that capacitor more slowly (meaning that the charger wouldn't be able to be used for a bit).