I just had this conversation with someone at work

It's an interesting topic -- I think that in some cases -- like your little one that needs the warmth, clothes are perfectly acceptable. I see so many people walking their dogs in winter (I live in Western New York) that look absolutely miserable because of the cold, snow and ice. Especially dogs with short hair -- they don't have the protection a husky or other long-haired breed might have.
I know some people who put boots on their dogs, too. In an area like mine, it can really help prevent frostbite or other pad damage from ice and salt on delicate paws. In hot areas, it can help keep paws from getting burned.
I think as long as the clothes serve a practical purpose for the dog, it's a good thing. I'm definitely not a fan of costumes or the dressing up a dog for the sake of making it look "cute".... usually they just look uncomfortable. Let kids be kids and let dogs be dogs!