I ride 365 days a year in weather that ranges from bitterly cold to pleasantly warm.
I commute 26 miles, round trip.
My greatest difficulty comes on the days in between bitterly cold and pleasantly warm.
I start out chilly and I end up over-heated.
I have found that a good wicking long-sleeved foundation shirt, arm-warmers and a vest give me the greatest comfort range.
Having my shoulders and armpits exposed to the wind, but with my arms and torso protected, seems to enable my body to best take care of its own temperature regulation.
As for gloves, I have spent more money on gloves than any other item of clothing.
One pair of gloves does not adequately cover all conditions.
The best combo seems a thin polypropylene liner, a thicker wool liner, and a breathable water-repellent shell (Pearl Izumi).
Between the three, and combinations of the three, I can usually find something that works.
For the very coldest days, nothing has worked except for a semi-lobster glove made by Pearl Izumi that has individual glove-fingers for the thumb, index and middle fingers, but which combines the ring and middle finger in one glove-finger.
A also wear tights under baggy shorts.
I like the baggy shorts 'cause they have pockets, and I think tights all by themselves look a little silly (at age 59, anyway; at age 18 I'd ride naked and feel OK).
I've found that having windproof and water repellent material on the fronts of my tights, and more breathable materials everywhere else, gives me the broadest comfort range in snow, rain and dry cold.
On very cold days, I wear booties over my mountain bike shoes.