I live at or near the North/South Pole, what considerations are there for ceiling mounted IBs in colder climates ?
The drivers themselves are pretty bulletproof. Until the voice coils and suspension warm up the T/S parameters are slightly changed. One enterprising fellow reverse mounted his drivers (fame and magnets in the manifold), thus keeping the metal parts of the speakers in the heated section of the house. He found this improved the performance during the colder months. Implications regarding heat loss through the manifold are those of convective loss through the cones. If this is problematic or worry some, use a removable insulated door or plug that can be quickly removed when the IB isn’t operating.