Correct me if I am wrong but removing the monarchy would require a constitutional amendment. Which is a tricky business in itself, but I would bet that when Canada does attempted an amendment every province and political group/party will want their own amendments attached as well.
$1:
In the case of an amendment related to the Office of the Queen, the number of senators, the use of either official language (subject to section 43), the amending formula, or the composition of the Supreme Court, the amendment must be adopted by unanimous consent of all the provinces in accordance with section 41.
I cannot see every province giving its consent to the amendment, especially Quebec since they still haven't endorsed the constitution. Nor can I see Quebec supporting something they know they could never control. Nor to I believe that NL, NB or NS would support it. Alberta may also see it as another attack on Canadian tradition and culture, as would many social conservatives.
Also removing the queen removes the protection Canadians get internationally. Little known fact but any Canadian overseas in need of assistant can go to a British embassy if they are unable to get to a Canadian embassy. Same goes in terms of evacuations, if a war broke out some place and the British had troops there helping their citizens those troops must help Canadians as well.