They wouldn’t be a State. They’d be a Territory. Like, say, Guam. Only slightly bigger in land mass.
Greenland is about 4.2 times smaller than the United States:
Greenland: The world’s largest island, with a surface area of 836,330 square miles
United States: The fourth largest country in the world, with a total area of over 3.8 million square miles
Greenland is more than three times the size of Texas, the largest state in the contiguous United States. It’s also the third largest area in North America, after Canada and the United States.
Guam is about one-quarter the size of Rhode Island, which is 1,034 square miles in area. Guam is 212 square miles in size, making it the 32nd largest island in the United States.
Guam is also about the size of Chicago. It’s located in the North Pacific Ocean, about three-quarters of the way from Hawaii to the Philippines. Guam is 30.17 miles long and 4 to 12 miles wide.