You will need a coat. Down, wool, or synthetic just make sure it's big enough to fit over a few layers. A good basic winter kit list would be:

• Winter coat, choose warmth over looks. Everyone looks like a fool here in January, but we don't freeze to death.
• waterproof boots, 1 size too big for extra socks
• 6-7 pairs of wool socks. Smartwool, Darn Tough, and LL Bean are good brands. You want the highest wool content you can find, as wool will continue to keep you warm even if it gets wet. Cotton and synthetics will not.
• Wool or high-end synthetic long underwear, at least 2 sets of bottoms. The LL Bean wool bottoms are pricey, but worth it. I have 2 pair that I've been rotating through for nearly 10 years and they're just now needing some minor mending.
• A few decent wool sweaters. Get one or two before you come, then haunt the thrift stores local to where you're staying and pick up a few more.
• Good warm slippers for being inside. If your feet are cold, the rest of you is cold too, and floors get cold in the winter here.
• A warm hat. Basic wool watch cap is a good, affordable choice, just make sure it covers your ears. It's not a fashion accessory, it's to keep your ears from literally freezing off.
• Sunglasses. Snow gets really bright in the sun, as bad or worse than tropical sun reflecting off the water.
• Good gloves, two pair: one thin, lightweight wool with the touchpad-compatible thread on the fingertips so you can use your phone without taking off your gloves. Then a thick, waterproof pair of gloves or mittens (mittens are much warmer, but you sacrifice dexterity) to go over the thin ones. You'll need the big ones for walking, scraping ice off your car, shoveling, etc, but you'll enjoy the thin ones underneath when you have to actually use your hands.
• if you have or will have a car, get a good wool blanket or decent sleeping bag to keep in it, along with a bright red handkercheif, a box of protein bars and a big bottle of water. If you get stranded in the snow or run your car into a ditch, tie the red cloth to your antenna or somewhere it will be very visible to passing cars, and climb into the sleeping bag to wait.