Last cold ride was -26C and I found trying to breath through the nose was a hardship. But the mouth was not the greatest, as the old throat was drying out severely. Best result for myself was to stop twice during 30 minute ride and use some kleenex that I brought along. This let me breath through the big ol schnose well enough.Stopping was a drag but breathing seemed to demand priority !!
At that temp it seemed i was pedalling at a steady rate not overly exuberant. Therefore not needing to breath at excessive rates.