friends here who abandoned their cold weather clothes regretted it. Friends who kept all sweaters and some jackets and raincoats(including me) are happy they did so. In short I wear sweaters most days (and all evenings) November through March, and sometimes a lined jacket or fleece jacket. I usually add a hat and gloves. If you travel North during that time, you will be comfortable wearing your winter coat to the airport.
At all times of the year, you will want to take along a light cardigan sweater or jacket when you go out because restaurants and theaters can be very chilly.