It's probably anyone's guess how they will treat you considering the rules seem to change on the fly but....
Do you have the Canadian version of a CDL (Commercial Drivers License)?
Are you being paid to make the delivery?
If you have both of those, you have a strong case, that it's a commercial delivery and that you are not just using a technicality to try and get around the rules.
If you are really on vacation and just got a discount on a one way trip, I could see an ornery official turning you around.
PS: Odd item, I was looking on Google Maps...is there really only one road that crosses from Ontario to Manitoba? (the other provincial borders have multiple roads crossing, so you could try a different one if you get turned away)
