I have been buying my groceries in the States for some time now, even with the difference in the dollar things are an awful lot cheaper. See: https://www.crossbordershopping.ca/us-grocery-shopping-canadians

I have never been asked by customs to pull in for a check when I declare groceries. 

Of course it goes without saying that anyone who buys their booze in Canada (with the exception of Quebec) needs to be committed to a psychiatric facility. I always get my booze from the US at a fraction of the cost that they charge here. Usually I stay over 48 hours or... there are lots of "special" suppliers around.