Gah, forgot to finish part II of my post.
Let’s say we set an arbitrary number for statehood. 100,000 is a nice round number, and big enough out of the small numbers of population. (Hell, we can double it to 200M if y’all want!)
How long do you think it would take Greenland to hit those numbers? And then apply for statehood? If they have 56M now, with a huge amount of natural resources (including rare earths!), I’d wager there would be quite a lot of companies moving in to start mining operations, expand the fishing industry, and so on. And each of those jobs generates what, 3x? 7x? in auxiliary jobs: restaurants, hotels, construction, entertainment, etc etc etc. Even if these people don’t become full residents of Greenland, they’re still part of the residing population and will likely be counted towards statehood population.
If we actually purchase Greenland in 2020, I would guess it becomes a State by 2030 at the latest.