Even the digital ones just say "-40.0C" at about 6pm, and won't show anything else until 17 hours later when the sun comes back, and they creep up a few degrees.
I rode my bike in yesterday at around -45C. The snow drifts were too big today, so I walked for 35 minutes instead.
I don't think anyone would ever ride a road bike in the winter, it would not be possible with the snow the way it is (deep, often drifting, rarely cleared)
Tons of people up here ride "fat tire" winter bikes with up to 4.5 inch tires. They ride the downhill trails right through winter.
(I used a cordless drill and just drove them through - took 30 minutes all done)
It's not clear why your thermometers don't register below -40, unless it's a legacy of the mercury thermometer limitation baked into the product (or frozen in, so to speak).