Ifseasonal fisheries and fisherman housings can be called "settlements".
While the portuguese claims were more or less acknowledged IOTL (at least in a first time), it didn't provoked a real demographical or economical boom : Africa and Asias were much, much more profitable and gained all the focus, and later Brazil.
You'd need a PoD in the XVIIth century, probably both a French and Dutch screw (maybe British as well), allowing Portuguese to create secondary colonies on the region, and you shouldn't expect a *Canada out of this but rather something akin to Portuguese holdings in Africa and Indian Sea : coastal control and more or less enforced suzerainty on the hinterland.
A Portuguese-screw big enough to remove Asian/African/Brazilian focus would probably remove the possibility of launching a new wave of colonisation in a totally different way.
One thing you're overlooking is that the holdings in India and Africa received thousands of settlers early on, but with mortality rates very high in those regions. Until 1600, more Portuguese emigrated to Africa and Asia than to Brazil. However, records at the hospital in Goa show that within 2 years around half of the arrivals perished of tropical diseases (malaria, typhoid, diarrhea due to contaminated water, etc). This was the same in Batavia, the Dutch East Indies for instance. Luanda was founded with five times as many people as Plymouth Colony, and here too their numbers dwindled due to the disease ridden region. The descendants of the fewer than 100 men and women and children who arrived on the Mayflower in 1621 numbered 80,000 by 1920.
The harsh winter of North America north of the Chesapeake Bay was actually helpful to European settlement in the region, as these winters tended to kill parasites. This led to New England (New Netherlands too) having much higher rates of natural growth than Europe, and even than Virginia or Maryland (where the marshy lowlands hosted parasites and mosquitoes). Assisting the much higher growth rates in North America than Europe was the lack of large scale warfare, abundant land, few famines famines, and the spatial settlement of settlers on large homesteads rather than clustered villages.
All of this this made the population of New France, Acadia and New England grow much faster during the 1600-1800 period. Not surprisingly once large towns appeared such as Boston, their population growth rates were similar to those of towns in Europe (due to the lack of hygiene and prevalence of communicable diseases). However, since only a very small minority of inhabitants lived in dense towns (4% of the total), this was a mere blip in the demographic growth of New England, New York and New France.
In addition, in the new world settlements, men and especially women tended to marry younger than in Europe and therefore have far more children. The average in New France was 8 per woman, in Acadia it was 10, in New England around 7. The reasons being that the abundant supply of land made dowries unnecessary for women to be marriageable. This led to women in North America getting married around 8 years earlier than in Europe during the 17th century. Also, unlike Europe where many poorer girls in Catholic Europe joined the religious orders, in New France there was always a shortage of girls for the convents. As for men, in Europe, the average marrying age until the 18th century was in the late twenties (the 19th century would lower it). This was often due to the need to save up some money to buy land or learn a trade to become attractive as a prospective spouse. In New France, New England, New Netherlands, these things were no longer were a concern, because once an area was fully settled new lands were opened up to settlement further inland and further west.
If Portugal were to settle this region around 1520, with the same numbers they did in Luanda at its inception (around 1,200 or so during the first two years), you'd get a population of between 1.2 million to 1.9 million by 1800. That is after 278 years with not a single immigrant ever arriving. While that may seem incredible, I'd like to point out that in similar circumstances, the most of the world's 3.5 million Afrikaners today can trace their ancestors to around 1,000 individuals. The downside is that certain genetic defects become more common in a population that largely inbreeds amongst itself with few new immigrants being added.
Another place to make a comparison, in 1763 France settled 12,000 French in Cayenne, French Guiana, over 8,000 of them perished the first year. The Saint Lawrence valley received fewer immigrants during the entire period of French rule, yet today their descendants number upwards of 10 million.