I have two heat pumps (gas not available in my neighborhood). One of them was installed this past October because the previous one was destroyed by a tree during a storm. Long ago, I decided not to freeze during cold weather, so I keep the temp set on 72. A couple of mornings during this past cold spell, the temp dropped to 66. Long story short, the installers didn't do something right and the heat strips weren't coming on. So the heat pump was keeping a reasonable temperature when it was 5 degrees outside, and in the teens during the day. That's pretty good for a heat pump without aux heat, even though it was running constantly. My house is insulated to the max though - R60 in the attic, 13 in the walls, and 25 in the crawlspace. The crawlspace is also encapsulated, and the lowest temp under the house was 55.
If you'll recall, just over a year ago it was even colder around Christmas. Low near zero, high one day only about 10, but we didn't have the ice and sleet then. I think much of Mississippi did though,
Just got my power bill. It was for 31 days and was read Jan 31, so essentially for the entire month of January. Electric part was $228 not including tax. Something around 2000 KwH at 10.08 cents per KwH for the first 1400, then about 10.9 cents for all over 1400.
That was pretty darn good since I keep my house at 73 all the time on the lower floor, and 70 during the day/67 at night on the second floor (where all the bedrooms are). Average temperature for January was 39.0 with 796 heating degree days.