Good luck fellers,
The same bit of bad luck hit me last September on my Trans Lab trip. It was Hurricane Ivan or Earl - I can't remember. I had some very poor weather driving up through Quebec like you two, it was beautiful through Labrador and NFLD for the most part, but I got socked off the ferry in Sydney and most of the whole way home. Stay safe.
You probably won't need that spare tire on the BMW.... I hope you won't need it anyway.
My ride report is attached to my blog which is linked.... September of 2010.