Of course it is. More efficient system, better insulation, etc. But your present system would consume even less energy than it does now if you took steps to minimize the temperature differential inside to outside. Maybe not a LOT less, with a hyper-efficient house like yours, but less.

Yes, your system "works harder" for a little while to bring a cold house back up to normal temperature than it does while maintaining a constant temperature. But all it is doing is replacing the heat lost during the period when it was "working less hard" because of the reduced temperature differential. Lower differential = less heat lost = less heat to replace.

As you [Scotty] said, "You cannae change the laws of physics."

tanstaafl.