Being diabetic, cold for me is much more intense than for many of you younger guys, especially you Northerners. Low 30's and 20's is real damn cold for me.
If it is very cold, I have a layer of silk under a layer of merino wool long handles. (will leave off one or the other layer if not quite that cold.)I have heavy wool trousers or a pair of medium weight wool bib front pants that I will wear. Next, I wear a Pendleton wool shirt under a wool sweater. Next I have either one of Teresa's pull over shirts or Ron LaClair's grey shirt. I have a heavy coat that I have been using as a last layer if it is both cold and windy, but in the off season I have acquired an Asbell hooded pullover, which I hope will become my outer layer.
I have every weight and fabric hat you can think of, so cold or wet I am fixed up fine on head gear. I also have cold weather scarves and face masks.I use wool or fleece gloves as well as hand/foot warmers.
Usually I wear leather field boots, but in really cold weather, I use -40% pack boots.
With all this, I still can't stay out as long as I used to. After 2-3 hours, I lose feeling in my feet, which surely takes the edge off the fun.