First can I ask are you using a infant carrier/car seat or a convertible car seat that will stay in the car?
For a carrier, I love the Bundle Me. But at that age, depending on the babys size, a convertible seat is sometime more comfortable. So then a coat I think is better, since they go from car to house or destination and back. Plus she may want to enjoy some outdoor time, in the stroller, or a wagon in the spring. I think to thick buntings, and snowsuits make it hard to securely hold you little one. And I know Madeline is not quite ready for long outing in really cold weather. I think a mid weight jacket I can layer under, i.e. onsie, t-shirt, sweater, jacket. If it's really cold there is baby termal underwear too.
While my son was in the the infant carrier I used the bundle me and that really was a lifesaver. It was so much easier (and cozier) than putting a coat on Jason. Now I'm using a lightweight coat with a hood, but I also have a fleece suit from lands end that I plan on using when it gets colder.
