The article doesn’t go into it, but a key advantage they have is that heat pumps move heat, rather then trying to generate it. So they can move a lot more heat into your house than would be generated by running the electricity they use through a resistor. This makes them effectively more than 100% efficient (the exact amount depends on temperature) as compared with burning a fuel or resistive heat.
Nice. Saskatchewan is very cold though (about 6000 heating deg days at 18C where I am and can regularly go under -30C in winter), so 200% would be pretty reasonable for a typical heat pump. As a comparison, Tromsø, in very north Norway is 5600 heating deg days.