I'm not sure why 0f is a big dangerous milestone in outdoor temperature. Is -18c/-1f really that different to -17c/1f? If anything, there's a much stronger argument that 0c is the dangerous milestone because that's when you get ice.

Really the only temperatures I care about on a day to day basis are like, freezing temperature (0c/32f), room temperature (20c/70f-ish) and various benchmark outdoor temperatures, like 30c/90f being hot and 40c/100f being potentially dangerous. You can +- a few C either way on any of those (except freezing) and it doesn't really make a difference. Cooking, even baking, is usually fine within around 10c. Sous vide is apparently a lot more sensitive but I've never done that.

Very occasionally I deal with something something like a kettle thermostat or boiler thermostat, where I might choose something like 100c/212f or 50c/120f respectively. I also use an IR thermometer for cooking pancakes, pizza and monitoring my wood stove - but neither Farenheit or Celcius are any more useful in that context.