The Portlands seem like a natural fit too.I thought of another site...Ontario Place and the CNE.
Hear me out...
If we take the entire Ontario Place and the parking lots at the CNE it is perfect for a mid-rise European style walkable mixed use community. You have offices in the upper floors and retail and restaurants all along a bunch of boardwalks near the water. This basically takes up all of Ontario Place and is phase 1.
Behind these mid-rise offices you can have taller commerical and residential that is on both sides of lakeshore. But we infill so that the first floor is above lakeshore. Basically lakeshore becomes a sunken highway that is unseen by this new area.
Amazon would keep some of the architecture of Ontario Place alive. Those pods become central hubs with cafes and meeting rooms. Guest lectures at the cinesphere.
On the weekends with the mixed use community the boardwalk would be busy and the pods are used by the entire community (the cafe potion is public).
The CNE would be no more. Other than the agricultural component it's just become a glorified midway anyways. Why not shift this all to downsview? The CNE, the agricultural buildings and the amplitheature.
As Amazon grows we could consider the future of the convention centre in the middle of nowhere. Double the size of the MTCC with Oxford and double the size of the ones at the airport.
Other than a few quirky historical buildings (which gives it character) it gives Amazon a blank slate to work with.
Now the other criteria...
We can give them enwave centre and the pods for a full year as a temporary office space until buildings are ready.
Transit...we can extend the streetcar from the Ex loop south and into the CNE grounds temporarily. Longer term we extend the Queen's quay tracks along Queen's quay and follow Martin Goodman trail behind the tip top building. Then it can follow lakeshore (south of the road) and loop into Ontario Place before going north to the ex loop (and the RER stop). Makes Harbourfront and Bathurst lines into 1 very long route.
It's also close to king west and liberty village so lots of residential and socializing options.