That is a false dichotomy. Housing is expensive in Canada due to zoning laws forcing a very inefficient use of land, among other reasons.
I lived in Europe for decades, so I know for a fact that making our streets pleasant to walk around isn't some weird utopia, it is the basic reality in many developed countries.
Developed countries have fewer children than necessary to maintain their population. If overpopulation is your concern, you have to look elsewhere, and the measures you need to prevent it will be different.