What are the US ground capabilities in extreme weather? Because from where I stand, I'm under the impression a Greenland invasion is off limit 8 months out of 12, and realistically the window is quite short, no?
Also if any french military asset is present when the US attack, we will see how determined the french military is following it's own doctrine (which dictates a 'warning shot' 24 hours before sending the tactical nukes).
For Canada and the Nordic countries, the weather on Greenland is business as usual, for all branches of the military.
My guess is as yours - the US military's focus on middle east and east Asia is of great disadvantage for them. Do they even get below -20 C for any longer periods at any base located on US mainland? Alaska, and some regions close to Canada, perhaps, leaving them with only some 10.000 personnel having anything near arctic experience, majority of which are based at the bases, not trained for front-action in artic climate.
Also if any french military asset is present when the US attack, we will see how determined the french military is following it's own doctrine (which dictates a 'warning shot' 24 hours before sending the tactical nukes).