Porsche has sold over 4000 Taycan in Norway. And there is alot of Teslas. Right now i have -12C in southern Norway. And we regulary have -20 to -30C every winter. Never heard anything about warrenty and cold wether.
My cars is left unused for weeks from time to time. And had this from another that I sold. https://smartercharger.com/collections/accessories/products/ctek-ctx-battery-sense Looks like car is waking up like once a week to charge 12V battery.