K.M. as a life long Minnesotan I will tell you that you cannot have only one winter coat! I personally think 3-4 are needed. I personally need a short down coat for outdoor activities; a longer down coat, preferably mid-thigh to knee length for dressier warmth on really cold days; a structured knee length wool coat; a shorter wool coat. These are the bare minimum basics.
For the sportier side, I layer like mad, I have down vests, fleece, primaloft jackets, and other various gear fabric in tops and bottoms to choose from. Now, I've lived in a cold climate FOREVER, so these items have amassed over time and they all see wear. For me they are wardrobe fundamentals.
I am a firm believer in wool of varying weights for tops, it's the most versatile and warmest. Fleece and cozy flannel are right up there too.
To stay warm while dressing up, I love a good thin thermal base layer like Cuddle duds, Smartwool, and wool or fleece tights. I wear pretty much whatever I want during the winter, but I am well covered when I go outside. If I want to wear a skirt, I will wear insulated pants, jeans or cords underneath while outside if really cold and take them off when I get to where I'm going (this does not work for elegant affairs, in which case you will have to grin and bear it somewhat...park close!)
I carry my shoes with me if they are not slush and snow appropriate. I do own a few pairs of boots that standup well to winter conditions. Timberland makes great leather boots that are also waterproof for every day wear. They hold up well too. Sorel makes a variety of great warms boots and some can be worn all day. Lots of good cold weather brands out there!
Good luck and stay warm!