Standard practice in Scandinavian countries is to have a small mains powered electic fan heater in the car & either run all night or on a timer. Only needs to run at low heat & fan speed, Jump into a nice toasty, frost free car even when at -30°C outside.
More free education:
Not only there is a heater for cabin but there is an engine block heater too, either directly bolted to block, on the coolant hose or a radiation heater somewhere near engine. Last one being least effective.
Usually 2hr warm-up is enough even in the coldest weather, also some concern for heating costs too.
The wirings are routed to a small plug on the bumper, there will be extension cord from that to post which usually has some sort of timer.
Defa is one of the more known brands for this.
Lesson #2 on auxiliary heaters (Webasto, Eberspächer) on request 😀