As a person that regularly crosses the border between the US and Canada, and has done so for over 65 years, it has been my experience, going into Canada is never a problem if you answer their questions the way they want to hear the answers. (this is with a car, or truck with a camper on it.) I have crossed over almost every possible crossing from Blaine to Ontario at least once.
In the literately 1000s of crossings, I have never been searched going into Canada, Not even a trunk opened. One time I had my Bronco stuffed to the roof and the Canadian border guard wanted to look, but then thought better of it when I said, "be very careful and prepared, when that back window comes down, stuff will start falling out."
I have been searched coming back into the US though, and they always want to see inside your trunk coming back.