First off, I'd point out that Quebec's immigration profile is significantly different from the national profile. In fact they are younger, they are a bit more entrepreneurial, and as you noted, they are more prolific in their birth rate. I think that is an example the rest of the nation should be following.
The key point to recognize, though, is that there are a lot of societies that are aging--and aging quite gracefully. It's not urgent that we open our doors and bring in everybody. Quite frankly, we have hundreds of thousands of people in our society who are already here and who are underemployed, unemployed, and unproductive. There are all kinds of steps--and I listed some of them in my comments--we could take that would allow those people to contribute to society in a manner that's going to allow us to sustain the quality of life we've created.