LO is 4 months old, can't sit by himself yet but is already 17 lbs and looking quite squeezed in his chicco carseat. It doesn't help that its become quite cold here in chicago, which means thicker clothes for the LO.

I am looking into getting a convertible carseat for him but am curious what other moms of young chubby babies do. If you get a convertible, what do you do when you are out and about...carry the baby or baby wear everywhere? (i.e. grocery store)