I'd be careful with charging the battery in-car in this cold. First, not every charger works normally at -20C, if at all. And it is not generally recommend to charge the battery at this temperature either. I have an on-board Noco charger under the hood of my Tahoe, and I disconnected it today, until this thing passes.
Otherwise, my block, oil pan and transmission heaters are the charm. They are on Wi-Fi timer/switch, under the hood, so I turn it on or off from the house, or set on/off time.
Another Wi-Fi timer/switch in cabin controls Little Buddy cabin heater and 12v DC power source that heats the seats.
120v cable is running along the rocker to the back of the truck. Under rear bumper (I back into driveway) it terminates with the camper-style waterproof port for the extension cord. One cord does it all.
Thinking about the water pipe heater wrapped around the catch can and its hoses, however I'm pretty much at the limit of the household outlet as it is. And I have yet to see if the can freezes at all.
My wife's Mazda sleeps through this cold in the garage. She uses my truck and appreciates a toasty interior very much in the morning. Hope the drive train likes the setup as well. And I'm happy as pig to avoid scraping the glass every morning, it is nice and clear.