Optimist
They nailed the current temperature rise. No reason to think the rest of the extrapolated curve is wrong.
possibly https://skepticalscience.com/1982-exxon-accurate-prediction.... (totally unverified - lots of links to the sources though)
Heretofor uninhabitable places such as ... greenland maybe?
Also, worth considering is that it is virgin territory for exploration for minerals and other goodies.
No shortage of water either.
But even all that aside, it is newly available space. If you can build a city in a desert (Phoenix, Arizona lets say) you can build one on Greenland.
As for soil, the creation of soil in Ireland and the UK took quite a bit of time.