Interesting to see this different confederation. I cannot help but wonder if at some point the constitution is radically altered - Quebec being counted separately from Canada East for one - even if they are not as separatist as OTL, I do think that they would insist on being their own province at the highest levels of government.
Incidentally, with Canada getting unified amidst war, I am surprised that noone suggested that membership of the upper house be perhaps limited to retired officers or the like, with the possibility of extending it to retired officers and civil servants down the line. At least in my conception thereof, the main purpose of an upper house should be to ensure that the elected representatives don't get too focused on short-term gains to fit their election promises and popularity to ensure personal reelection at the expense of causing long-term harm.
Quebec both gained and lost in this scenario. They've gained far more control over their senators than they ever exercised historically at the expense of the number of senators in the upper house. Macdonald has a very dangerous game moving forward.And the members aren't even settled yet! Historically, PEI and Newfoundland walked after Quebec, which was a major blow to the agenda (though Newfoundland had only expressed marginal interest overall, and despite the delegates being interested, they failed to sell it to the public back home). With Canada East (not called Quebec proper until Confederation) there's more a desire for local autonomy over the French language and Catholic Church. That said, it's largely a hope that they can govern their own affairs as a more autonomous province within a greater Confederation. So far, they just landed some spectacular ammunition with how the future Senate is likely to be set up. Though without everything codified Macdonald is planning on attempting to neuter them just a little bit.