They could of built and worked in different industries in the future as well. Farming was also really popular in New France. There were probably places in New France that had good weather. I think this is only possible if France won the Seven Years War or if it somehow kept it's colonies. And French Louisiana was actually established in 1682 not 1699.
Farming is a normal human activity so it's logical that the Canadiens were mostly farmers. But they didn't get rich by farming there, not like the plantation owners in the Caribbean. They grew basically the same crops as in France, and France has better soil and a longer growing season. The one thing Canada could really export was furs, and that did not correlate with high human population. There also were long wars against the Iroquois for control of this trade, and peace was not reached with them until 1701.
1682 was the year of La Salle's voyage, but he did not settle Louisiana. The first actual settlement was in 1699 at Fort Maurepas.
You can certainly have the population of New France be larger than it was.
-The 1685 expedition to Louisiana could actually arrive there.
-The Mississippi bubble could be avoided.
-Protestants could be tolerated and allowed to emigrate there (this may require a different monarch than Louis XIV ; maybe the Fronde succeeds?)
-The French government decides to ship a lot more convicts over.
But you're asking for the population to be
insanely large.