I live in Massachusetts where the mean low in January is 5F, and I’ve seen -10 and below. I’ve never seen someone bring car batteries inside. I haven’t even seen engine block heaters since the 1990s, but people with diesel cars used to use them in the winter.

Based on how the question is worded, the answer is probably a niche carmaker like Lotus or Jaguar (canceling all vehicles and going 100% electric in 2025).