Patagonia Infant Hi-Loft Down Sweater Bunting (one piece). Size 6-12 months. Note, this worked for two winters for us as the hands and feet can be cuffed when tiny and then opened up as the little gets a bit older! From Patagonia's website: "Our warmest one-piece bunting has a shell made of NetPlus® 100% postconsumer recycled nylon ripstop made from recycled fishing nets to help reduce ocean plastic pollution and is insulated with 700-fill-power 100% Recycled Down (duck and goose down reclaimed from down products). Lined with soft recycled polyester fabric, this bunting has a generous length to help keep extremities protected whether your little one is crawling, standing or sitting."