It was 10 degrees Fahrenheit here recently (that’s about minus 12 Celsius) and tonight it was warmer but not much, and my 2000 Audi A6 with the 4.2 V8 didn’t much like starting. The engine turned over very slowly the first second or so. I was VERY glad that I’d installed a massive battery that just barely fitted in the battery compartment. Anything smaller and I might well have had a no-start condition.
However, I later needed to remove the battery to move my BMW around (and its battery needs to be charged, so I’m using the Audi’s). Removing the Audi battery risks a lower-back injury, but then my assistant had a clever idea. The batteries I buy (and that, I hope, you buy) have a handle at the top, and putting a broomstick handle through it makes it easy for two people to lift out.