In Utah?! I think you are being far too cautious.

For at least 15 years I (and a bunch of other bike club members) rode our bikes all year, regardless of the weather, in Fairbanks, Alaska. One of our most fun group rides was the "New Years Eve" ride, which started at midnight on December 31, sometimes in temperatures as low as 40 degrees below zero.

I confess to being a wimp, my normal cutoff temperature was minus 10 degrees Fahrenheit. Not because I was too cold, but because it just wasn't as much fun, having to layer up to the point where it took significantly more work to bend my knees, and colder than that the bike didn't work as well, the shifters would get stiff, sometimes the pawls in the freewheel would stick and the pedals would just spin without providing locomotion.

As a rule we would wear exactly the same clothing that people would wear for cross-country skiing. Nobody thinks it's strange to see skiers out in sub-zero temperatures but for some reason they think it's extraordinary to see people on bicycles.

tanstaafl.