Aw! Ducklings! What kind are they? (I think I missed that post)
Speaking as a complete novice couldn't you use a less insulated/more ventilated coop for breeds like Chanteclers which were bred for Canadian winters? I'm not saying just a nest box and a run but maybe a platform with thick bedding, nest boxes, a roof, and short walls to break the wind?
My coop has no insulation. Just nice thick wood.