Something like this may work for you. The fill is compressible which is key. You'd almost have to feel it to make sure though. Not sure if they'd have it at your local MEC store, but on sale online, whoop!
Sorry in advance if the clicky doesn't work.
Re: Madame Ha
Thank you! I'll have to go and have a look
Also, I love that they call it the "Puffball" jacket.