Perhaps it is finally time for Canada to become a republic
There is an interesting essay in The Globe & Mail on the topic of Canada cutting its last colonial ties to Britain. The author cites the fact that Princess Anne's son must renounce his right to the throne (he is tenth in line) in order to marry his fiancée because she is a Roman Catholic (and a Canadian, although marrying a Canadian doesn't disqualify one from becoming the British monarch). He argues that the law that prohibits a British monarch from marrying a Roman Catholic runs counter to Canadian values. He is right. The British should abolish this law, but the Canadians should consider if their ties to the U.K. need to be such that the Queen is still the Canadian head-of-state.
The U.S. hasn't seriously considered trying to conquer Canada since the War of 1812, so the threat from the lower 48 isn't what it used to be. I doubt that the Royal Army would be dispatched to repel a U.S. invasion of Canada anyway, although perhaps they might send a token force for old time's sake. At any rate, Canada's link to Britain is now purely symbolic, and perhaps it is time to consider what the British monarchy is a symbol of.