Hang on, though.   Why are you tying supply management to American access to this market?   They are separate issues.

Supply management could be eliminated, barriers to trade reduced, and still there could be controls on the quality of what can be sold.   The American standards for dairy (and meat, as one other example) are lax compared to here.

More French brie at better prices?  Bring it on!   There are lots of other good products out there too that are too expensive in Canada.