I've read a lot on these boards about the price of duty at the border if I bring in more wine than the allotted 1.5L per person -- starting as low as a few dollars per bottle. I finally got through to the Canada Border Service. Here's the scoop for anyone interested: Going into Montreal from NYS...an example of a $20 bottle of wine (you must show receipt) will be charged a duty of $18.35. I was surprised and the woman explained that Quebec has the highest duty.
Needless to say, we will be buying any extra wine at the SAQ!