Siberia is vast, checking one town for it's climate is not representative. While most of the southern part of Siberia is relatively mild (like nothern central US) there are huge regions that are known for more extreme temperatures, in particular Sakha (Yakutiya): https://en.wikipedia.org/wiki/Sakha#Climate
The context of the point is that Climate change's max increase is only another 0.5celcius and at worst the currently too cold places will become warm enough to live comfortably.