Stupid idea. Humans are optimized for living on Earth. Living on another planet will have them dead.
I'm sure something similar was said to the first humans thinking of crossing the Bering Straight, the Atlantic, island hopping across the Pacific, etc.
Man was born in a temperate climate abundant with food (”Eden”). Now look how many races man has adapted into across every corner of the globe in every climate.
We are explorers and the ultimate adaptable species. This is a temporary planet and Man's destiny is in the stars