(this is an unrealistic scenario, but one that I thought might be an interesting game)
ScenarioAfter leading the Liberal Party to a majority government in 2015, Justin Trudeau's government goes through with changing the way Canadians vote. However does so in an unexpected manner, in May of 2018 a constitutional amendment is passed making Canada a Republic.
Canadian Elections are now fought under a fixed four year term starting in 2019, with a separately elected House of Commons and Senate.
Structure The Canadian House contains 338 members, the same as before. Meanwhile the Senate is elected but while officially Non-Partisan contains obvious partisan ties. Their are 53 Senators, 5 from each Province and one from each territory(they serve a 6 year term). The President replaces both the PM and Governor General as the Head of Government and State. The President serves a fixed 4 year term (they are not term limited) and has much the same power as the USA President would have. All races including for the Presidency use IRV, Elections for President are only based on the PV.
The 2019 Election-Entering 2019 President Justin Trudeau is preparing for Re-Election and may still be challenged in the primary , while the Conservatives and NDP have wide open fields for their nominee. Potential Candidates may be for the NDP
https://en.wikipedia.org/wiki/Next_New_Democratic_Party_leadership_electionFor the Conservatives
https://en.wikipedia.org/wiki/Conservative_Party_of_Canada_leadership_election,_2017For the Liberals
https://en.wikipedia.org/wiki/Liberal_Party_of_Canada_leadership_election,_2013Here is the complete list of MP's
https://en.wikipedia.org/wiki/List_of_House_members_of_the_42nd_Parliament_of_CanadaI will continue the introduction on the next post