I hear you on all fronts. I've only read half the comments, but basically -- I understand your needs (long, layer-able, warm) and desires (yummy fabric!!) and also the reservations about this coat.
It can be SOOOO hard to find a dress coat that works for Canadian winters.
I still don't have one, myself. Now I'm in a climate where it is less important, and I more or less decided that when I do get a really long coat it will be a puffer, because, well, it will be easier and more lightweight.
Having said that -- I would love to see you style this one and layer it with what you would be wearing. It can be so important. Boots, hat, the works. Tryons without styling can be so deceiving.