I agree that Montreal would obviously be interested, and would likely pull the trigger on a deal after July 1st if Andersson was willing to sign an extension (providing the cost was right obviously).
Would something along the lines of the Calgary 1st, Alex Newhook and Jayden Struble be something that Calgary would consider? Newhook and Struble can jump right into the Flames lineup (under team control) while adding another first is never a bad thing.
Habs defense would certainly be much more balanced if some deal could be worked out:
Hutson - Andersson
Matheson - Guhle
Xhekaj - Carrier