As an example, it may start becoming more economical to include heat-batteries (I forget the name) in house construction such that they retain heat and radiate

As an example, it may start becoming more economical to include heat-batteries (I forget the name) in house construction such that they retain heat and radiate it to maintain a not freezing ambient temperature inside a house. That, along with insulation, and some rather moderate changes to behaviour, could entirely eliminate the need for electricity-use during night time hours. We don't know what ingenious and wonderful things people may do when the real-cost of electricity at night is exposed to them.