I'm in the IE (near Fontana) as well. Now it's getting to be 38-40 in the AM, colder is coming as it'll be dark again end of Dec. in the AM.

I dress in layers and it works so much better than one jacket that has lots of space in it for wind to circulate in.
Base layer long sleeve, thin merino wool sweater, then a Performance Transformer jacket that cuts the wind and elements. I sweat very easily so it's tough to not be wet underneath when I come in. The wool takes care of that as it's still insulating when wet.
Cycling bib shorts with knee warmers (soon to get some full leg warmers) is fine for lower areas. I'd probably appreciate some overshoes or wool socks as my feet are now feeling the cold, even with mountain type shoes.
I use a Buff that I can pull over my head and it'll cover my neck and also can flip it up to cover my nose and mouth. Pretty versatile item. Keeps the wind from cutting through to my head/ears so easily.
I wear full finger gloves, not cycling specific, they do well.

I was toasty this AM and felt I could have taken the arms off the jacket and still been fine.
YMMV