It do fortunately not get that cold in little old Denmark, 14 deg F / -10 deg C is cold these days, and not very many of them during a winter. Last -7 deg F / -20 deg C i remember if about 40 years ago Also longer cold spells in my youth, back then Denmark had ice breakers, and they was in use just about every winter, but they was sold for scrap years ago.
BUT ! we will need at least 14 deg C / 57 deg F to enjoy shooting, personally after having worked / travelled the warmer regions of earth when i was young, 20 deg C is pretty cold for me already, even now when my weight have doubled and i pack a lot of " insulation "
What types of wood do you use there? Here we mostly use oak, maple, locust and sometimes walnut. Pine is a guaranteed eventual flu fire. I'm not familiar with the trees in your area.
Oak - Beech - Ash - Birch seem to be the most prevalent, my Friend have huge maple trees, we have also burned a apple tree and will soon cut down a little pear tree. But hard wood in general.