Stately Fugger Manor - a rambling Craftsman home - underwent extensive renovations in 2016-18 (it may one day end...), including lowering and finishing the basement, and replacing the baseboard heat with an electric heat pump and natural gas furnace backup. The exterior walls of the main and upper floors were insulated about eight years ago, but even still, the average winter bill had crept up to the $500 range. The home was always kept colder than normal.
The first winter bill, post renovation? Keep in mind, we are essentially now heating nearly double the space and I ran everything around 20-21 degrees all day (no dropping off while we were out, which we came to understand is actually detrimental to a system like this: $101.36.
Except in the coldest days of winter, the main floor stays at about 19.5 degrees without much intervention of the heating system. Finishing the basement made a HUGE difference, on top of the heating system. Now, my gas bill has crept up, but that's mostly from switching from electric to gas cooking appliances - but nowhere near the rate at which Hydro has shot up. It's amazing what kind of energy savings several hundred thousand dollars will effect!