The point of going to Mars is to give humanity a plan b, not as a vacation with lots of hiking and other outdoor leisure stuff. Considering how much time an Earthling spends indoors, it's not a huge leap to spend all of one's time indoors. Building underground and staying inside. There, problem solved. Makes a whole lot more sense than making our first attempt at colonizing a whole new would at the distances we'd be looking at with Titan.