I remember days like that too. Every winter we got a few days of -25 to -30 F temps. It was normal. I would get up at about 3 am to start my car so that it would start at 7:30 am.
I just checked and my car battery is 5 years old. For some reason I was thinking it was only about 2. I checked the water level for the first time ever and it took nearly or maybe slightly more than a pint.
BTW, has anyone noticed how expensive Car batteries have gotten? I believe the price has doubled in just a few years.