I've been wearing a bathrobe as a cardigan for the past month...

[Mister Obvious]

I feel it's important to clarify that I would not wear the heavier robe out in public. Around the house is fine, but I wouldn't wear the heavier robe out of the house... I would wear a long wool coat, in cold weather. Out of the house in the summer I might wear an ideal lightweight/sheer robe with the right outfit.