Trisk, I really don't think you need a down coat for Boston. Northern N.H., maybe. The temperature varies so much. The normal winter daytime temp is usually 25-38. I think prima loft with other layers underneath would be sufficient. I have a wool dress coat that's fine and a regular EMS parka type thing for regular wear. I use a Go lite jacket over my layers of fleece, wool, and silk when I'm x country skiing, snow shoeing, hiking. Some of the layers come off when it's in the 40s.
So even though the nighttime temperatures are in the teens or single digits now, the days are around 30. Just gt good gloves and a hat!
Robyn

Sorry your daughter got sick! This is the first winter I haven't had bronchitis, since I moved here. Maybe since I'm not around those nasty kids anymore...