I think Australian style STV would work best for Canada, although maybe fewer Senators for some of the maritime provinces, and more for Ontario and Quebec?
Would Greens get seats? Or would the Senate just have provincial parties?
If it was done FPTP I'm sure most provinces would elect a mix of parties and base it more on the person than the party. I can't imagine BC having only Tory senators.
Depends on the region. For example, in Quebec the only Tory who could be elected province-wide might be Max Bernier. For the Liberals it's Trudeau- and both men have prime ministerial ambitions, so they wouldn't run. BQ wins both under FPTP.