We have an almost 11 month old. He will be 14 months in May. He is currently using an infant car seat still because of how cold it is where we live (easier to put the cozy cover and not have him be hit with the cold. However, he is being transitioned to a convertible car seat here in a month or two. Would you use the same car seat for your May baby or buy a new one? (It’s in good shape. However, he gets sweaty in there. And thrown up and poop has happened)