Seems odd. It certainly doesn’t get as cold as Alaska as it does here in New England but Subies tend to be the weapon of choice for lost of people because of its reliability in bad weather. You see them everywhere here.
Does the car crank but not start? If it turns slowly or not turn at all, it could be that your oil is too thick. Subary recommend 5/30 but there is a lower viscosity oil that may actually work better in really cold climates, like 0/30.
Cold decreases the peak capacity of the battery but one would imagine that it should start fine after leaving it for a half hour. Oblivion’s suggestion is a good one, to find another battery. Some are better than others at performing in cold climates. Some are actually made to perform in cold weather.
If you or your husband knows how to use a multimeter, perhaps see if you can hook it into the a fuse somewhere and monitor the voltage while you’re driving. It should be around 14.4 V while driving.
If it isn’t, your battery isn’t being charged properly.
Make sure you drive the car a bit every day. Blow the spiders out of the exhaust by running it a bit of a distance. If it is a stick, rev the engine a bit higher by running in a lower gear. It will make sure you charge your battery but also blow some of the water out of the exhaust system - this is unrelated to your issue but that will help slow the rusting process of the exhaust.