The more I think about it, ADQ leader Mario Dumont's "autonomist" position is a really good one. It just might wake up the provincialists in other provinces.
For a while now, federalism has meant unitarianism. More and more power was centralized to Ottawa to enlarge the unitary state, at the cost of decreasing the autonomy of the provinces. As subjects in the Soviet Union learned, centralization is dangerous.
It's better to be ruled by someone close to you, who you can readily access, than by an impersonal apparatus thousands of kilometres away. If a province starts to oppress you, you can always move within the federation. As provinces compete, the nation-state's citizens have options.
Having said that, being part of a larger federation has its benefits. Trade, defence, and international influence are better handled by larger states than small states. If Quebec were to separate, 7.5 million people would lose the benefits of mostly free trade within Canada, would have to fund a military on its own, and would have the global pull of a country like Finland.
Keeping government local benefits regular people, but so does staying within a united Canada.