Whenever Canada experiences product shortages at home, almost invariably the first route that gets cut-off is anything destined for the US, especially when it comes to medication. And at the rate things are going with BAC water, the more Americans buying it is likely to cause shortages pretty quickly.
A lot of people probably don't know or remember this, but up until a few years ago (at least 10 I think, maybe more) Tylenol with codeine and several other codeine products along with a handful of other meds that require a prescription in the US were available OTC in Canada and a lot of pharmacies would ship to US customers. Health Canada is a little more nimble than the FDA when it comes to putting a stop to things, and Canadians in general tend to be a lot more compliant about such things when their livelihood is at stake. It also has the potential to be far more problematic for US customers because it is a labeled pharmaceutical and not just unlabeled vials of mystery powder. Personally I would never have it shipped, but wouldn't worry too much about bringing across the border in my car.
I guess my point is relying on Canadian sellers for BAC is likely to be very short lived.