I hope this is okay to post here. I know bulky coats are NOT safe in carseats, and I'm looking into warm non-bulky jackets for my boys for the upcoming winter (we're in the northeast). They are 5 and (almost) 3. I know fleece is a great option but I'd like to find fleece that is specifically rated for colder temperatures. I was browsing LL Bean's website and it looks like their toddler sizes are 2T-4T but boys sizes don't start until 8?? My 5-year-old is a peanut but I think he still needs a size 5 for sleeve length. If it matters, both boys are in Radians. My other question is, usually the boys would be wearing a long-sleeve tee under their jackets but occasionally will wear sweaters, which I then need to loosen the straps with the added bulk. Is this unsafe? It would be tee + sweater + fleece as opposed to just tee + fleece. Thanks in advance for any replies!