Wow, everything I ever learnt about electricity is turned on its head by this article.
I always understood that if a switch in a circuit was opened, then current ceased to flow. I also always understood that an electrical supply circuit is built on a hierarchical system of circuit breakers where the lowest level supplied the smallest number of devices, those a level up supplied a few lower level breakers and that the ratings of the breakers were such that the lower levels tripped first, which reduced the amount of current flowing, which then stopped the higher level breakers from tripping.
So in a country level network, surely it is designed such that a trip to a plug in the wall of the house trips first, then the house trips, then the road trips, then the substation trips, then the area trips, then the province trips etc etc.
So if one area is drawing a brazillion gigawatts of power, that area is disconnected and it can lo longer affect anything else, there is no such thing as potential current usage as long as that area remains disconnected.