Real talk- how cold is too cold?

Where I’m at currently it feels like 0° F and we are getting ready to get hit by an arctic blast. I keep seeing numerous posts online warning against people keeping animals outside for too long when it’s super cold.

When I posted about not wanting to go outside with my collie the other day in this weather, a few comments said that this was what I signed up for and the cold wasn’t bad enough to stay in. How cold is too cold? I want to do right by my collie but I don’t want her (or me) to freeze…