The flexibility recognized in jurisprudence was related to discrepancies in the principle of proportional representation that exist within the same province, between representatives from urban and rural areas. Regardless, the Supreme Court demonstrated, in its decisions, that its interpretation was not simply based on a mathematical or arithmetical imperative.
Also, in practical terms, our laws and even the text of our Constitution include small exceptions to proportional representation. I think of the senatorial clause, which establishes that a province is entitled to at least the same number of members as senators. This was also upheld in 1982 and is now very explicitly protected by section 41 of the Constitution Act, 1982. There's also an equivalent clause for the territories. In that particular case, there's no basis for the clause other than the actions of the federal Parliament. Thus, an exception to proportional representation was made for the territories through the same procedure that is being used to try to adjust the electoral map and electoral representation here.
In the case of the Senate, the exceptions have increased over time. Proportional representation was not the logic that prevailed during the allocation of Senate seats in 1867. For example, when Newfoundland joined, it was given seats, but they did not come out of the number of seats belonging to the Maritimes.
That means there's a logic from 1867 concerning the allocation of Senate seats that was enshrined by the Constitution, which is is hard to amend, but it does not prevent small exceptions through a unilateral constitutional amendment, if only for the territories and Newfoundland.
The principle of proportional representation therefore cannot be considered as absolute, as though it were the only constitutional basis in question in this type of extremely sensitive matter.