Where to get infant winter clothes for fat babies

My son is 2 months but is fat. He wears 6 months clothing but the pants are too long, anything smaller and they will be too tight. No jackets fit because he has like 3 chins 😂 so it’s super tight or it fits, but the arms and hood is wayyy too big. Same with hats, either too small or way too big.

He has no winter clothes. We’ve gone to Walmart, target, Sears, Kohl’s, Carter’s and we previously bought a bunch of stuff from babies r us before they closed but nothing fits!

So mommas of fat but short babies, what do you do?