Congrats on deciding to get into winter biking! Unfortunately, your questions are a bit tough to answer.
Climate and personal needs are well, so specific. What would be helpful is at least hearing what the range of temperatures and conditions (rain, snow) that you'll be biking in. It sounds like winters in Minnesota are a bit different than Glasgow (unless you're talking Glasgow, Montana!). And hearing what Glasgow is like, I can only tell you what would work for me, which may or may not work for you.
Other things to consider are that the same temperature feels different in the dark or sun or clouds or shade or Oct or March. Wind makes a difference in how I dress. For years I had a miserable time with a commute that if it was a strong northwest wind, my zig zag route would have me bike with and against and with and against..., and dressing was a compromise--get too warm with the wind and stay comfortable with the "into the wind" stretches? Or comfortable with the wind and cold going into it? Length of ride (one fellow was admonishing those who shelled out bucks for good winter cycling boots when his $20 pair of hiking boots worked just fine. I asked how long his commute was. "3 blocks!" One could about do that in flip flops in January even around here if needed...)
My clothing arsenal for 0F to 65F (-18C to 18C) includes: jerseys, short sleeve polypro t shirt; long sleeve light, mid, and heavyweight polypro shirts; cycling windbreaker, hooded double layer windbreaker; cycling shorts; light weight tights, mid weight tights; lined wind pants; light and mid weight polypro long johns; fleece pants; thin wool beanie that fits under the helmet. Over time I learned to make a spreadsheet with all the clothing, and what temps they were used. Hand and foot wear are also included.
Note that no arm or leg warmers are listed, which gives you my opinion of what I'd tell you to do.