It always puzzles me when I read that sort of report because ours works down to 28 or even lower (to keep house at 69 or so), even though it's a low-tier Coleman trailer unit and is 16 years old. But I often shut the HVAC system off entirely and use electric oil-filled radiators, because they're so much more comfortable.
I think its because ours are designed to be better AC units.
There is a feature called “emergency heat’ which basically just means there’s a massive element it blows air over. The electric meter nearly takes off when you turn it on.