At barely 100 square km. the City of Vancouver is a small piece of Metropolitan Vancouver (over 2800 square km). The population is 600,000 compared to 2.4 million for the whole lower mainland. The city's population density of 6000/sq. km. is already the highest in Canada while the rest of the region is less than 700/sq. km.

By the numbers it would seem that there's a lot more room for up-zoning in the surrounding municipalities, particularly since land gets cheaper the farther you get away from the core AND since much of the necessary rapid transit infrastructure is already in place.