I have two boys and they LOVE the snow! I only let them out for like 5 -10 mins bc they refuse to wear sweatshirts/jackets! I don't worry much about thier bodies getting cold, but I do worry about their paws. When their paws get cold they sit down where they are and cry so I usually have to go get them and bring them in! This is my 3rd winter though and they love the snow!
don't worry so much! too much worrying will only lead to disaster!
You'll know what you need for them when you see them out there! I knew my boys would never wear boots when they wouldn't keep on a sweatshirt for more than ooohhh 3 mins!