My 2010 heat pump is a Panasonic model. Panasonic, Mitsubishi, Fuji, Toshiba and others have Nordic-specific models. Several of these reach 1:1 at -30C, and some of them are reasonably efficient even at -25C, which is super impressive when compared to my 2010 model. Obviously they will need regular maintenance, keeping the radiator clean etc, and these are very thin and sensitive so you may have to get a professional to do it.

Edit: Looking at the specs for current Mitsubishi models, they are pretty decent (as in: Getting more out than you put in, and useful effect too) at -25C, reaches 1:1 at -30, or, for some, even colder. At optimal conditions you get 4.4 to 5.5 times as much out as you put in, depending on model and temperature.