Did you ever hear about baby sleeping bags? They are for infants and for toddlers.
Our three and a half years old son is still sleeping in a sleeping bag, and he is not going camping. He and his two years old sister are lying in their sleeping bags in their beds. Without a blanket and without a pillow. Maybe it sounds for you uncomfortable but it is not. It is a really safe way to put your Baby to bed, your Baby can't pull the blancet over its head. It is always warm because the body is covered, regardless of how actively the Baby may sleep.
There are summer and winter models with different colors and styles. It looks really cute when your Baby is wearing a sleeping bag.
Your Baby feels comfortable and protected, this could help your sweatheart to find a better way to sleep.