A milder winter is a longer winter

 That's only because it is super cold elsewhere, and we, in Toronto, are getting mild Pacific air.  

But the Arctic is going back to 60 below because the Atlantic plumes are stopping short.  They were following the unstable end of the Gulf Stream, and now that tail is wagging back south.

The Pacific plumes are in a standard 'pinwheel' which means lots of snow storms for us.  A standard winter has the plumes attacking the Yukon, which brings down very cold air on us, but no snow.  If the Arctic cold air mass is left alone, it stands alone.