Not for mine; a thin sweater (actually an old polypro base layer top of mine, cut and sewn to fit) keeps him warm well below freezing. If it's above freezing, his double fur coat keeps him plenty warm enough.

I would think that for less hairy dogs than mine, a jacket would be better than a quilt--he won't knock it off when he stirs in the night and then turns around three times before lying down again. Plus it can be used in the daytime if needed.