I bike every day. I bike commuted a few days a week for a few years and then decided to go whole hog and sold my car. I don't have an excuse now, so I bike regardless if the temp is way, way below zero F.
The few times that I have used a cab usually involved me needing to get the airport. I have not found a completely viable way to get there with the gear I need for a week or more away from home without taking my cargo bike. I am not comfortable leaving my cargo bike outside at an airport for a couple weeks, so hence the cab.
That said, when I am going out of town via airplane, I usually ride to my office (plus a train ride), which is then just a few miles from the airport, and take a cab from there. My co-workers are pretty sure that I am certifiably crazy.