For the most part I tend not to be traveling that fast in bad winter conditions and when I was using rim brakes they almost always worked well enough. I did have a couple of occasions one year where I hit the brakes at an intersection and they did absolutely nothing. I don't know if it was just that particular rim and pad combination or just the right set of conditions.

For many years I was changing winter bikes and equipment frequently, - trying to figure out what worked best. One particular wheel has moved from bike to bike and is now getting worn out from using rim brakes in bad weather.

So based on experience I do have a preference for discs but I'm not terrified of using rim brakes in the winter either. If I lived in climate with less extreme cold, my preference might be for rollers instead.