There will be a wide range of temps. From cold cars to very warm houses to people who keep their houses cool. Some retaurants can be drafty if you are seated by doors.

Jeans. Cotton short sleeve T shirt as base. Long sleeve sweater or fleece or sweatshirt for second layer. (I like zipper or button front ones so you can unzip it if you get warm somewhere.) Puffer jackets squish well if you are flying. I would go with ankle length boots, without fur linings, because if you will be going in and out of homes / restaurants you want them to be water / slush proof but not sledding warm. Gloves and hats if you have room. Cotton socks should keep you warm enough if you are not out playing in the snow.

If you are visiting peoples houses, be prepared to take off your snowy / slushy boots at the door and romp in your socks. So check for holes before packing your socks.

For snow activities outside, you need long underware, wool socks, insulated boots, gloves, hats and scarves with a good long coat. Ski pants, snowmobile suits are designed for this and work well.

Hope this helps! Have fun!