Call me crazy, but I actually think the Wynne Liberals will win another majority in 2018 allowing all of these transit plans to remain intact.
The main ingredients of Wynne's support base are progressives and millennials. Wynne's progressive credentials were damaged by the teachers strikes and the Hydro One fallout, which was the root cause of the decline in her approval rating from its mid-to-late 2014 honeymoon. Both those things are now behind her. Furthermore, thanks to the sudden boost the provincial economy is getting from the falling dollar/falling oil prices, there's suddenly no need for any real austerity measures anymore. We saw that in the 2016 budget with the spending freeze broken and hospitals given a funding boost, and with candy thrown to progressives like the student aid overhaul.
I expect the NDP to continue its decline to irrelevance, for the PCs to suffer from internal chaos over the competing forces of the base and those who want to moderate the party (we're already seeing a taste of this with the carbon tax file), and the Liberals to re-energize their appeal to progressives. Plus as the provincial economy continues to improve, and the Liberals head into the 2018 campaign with reduced unemployment rates and a balanced budget. All four factors will allow the Liberals to win another narrow majority.
The only thing I can see stopping this is if the PC Party actually succeeds in moderating itself while retaining its grassroots support among its largely rural base (critical to its funding, volunteer army, and GOTV efforts).
By 2018 Kathleen Wynne will be 65 years old, so if re-elected to another majority term she'll probably retire towards the end of it, around 2021 or so.