Hmmm, don't know how I missed this.
To please Lower Canada, the House still might be split 50-50. On the other hand, with the Maritimes already in the United Province, their will be no need for any Confederation.
What you might see as the decades progress is a need to restructure the nation.
One thing I'm certain of is that Canada will most definitely more centralised than it was in OTL (which itself was considerable, but with lesser provincial rights at the get go, you probably won't see British interference resulting in the loss of central power).
More thoughts on this later.