Trump is erratic and undisciplined and the whole MAGA movement is regressive, radical and dangerous and I am sure Lebensraum has some resonance with them. But there is obviously shit going on with the rhetoric on Canada and Greenland that points to control of the Arctic as being the driving issue. It possibly goes beyond the current executive and is some insane branch of long term US strategic thought. That suggests they probably only want 2 or 3 mostly uninhabited northern provinces plus Greenland under US colonial rule. Sucks to be indigenous (again).
Not saying those provinces should be given up under intimidation. But I doubt if even someone as stupid as Trump wants to deal with repressing a resistance movement on the US border. It seems more likely this is one of his famous "deals" (perhaps more accurately shakedown).