Just looking at the temperature range on Mars. It's 1.5x the distance from the sun as earth and the surface temp ranges from a balmy 70F to -225F.
Elon specifically has this dream of colonizing mars, but it seems unrealistic. Perhaps in the future there could be an outpost where humans can visit for extended periods of time, but living there forever seems kind of sucky.
Although it s a bit extreme, we need to start developing alternative places to continue humanity in case the Earth becomes uninhabitable (whether by our fault or by acts of nature).
Although frankly, I am not sure mankind should be saved. Organic life might be just a step to higher things, and possibly around the universe has only been a stepping stone to more rational machine life.