Well, that's the thing, though: the time frame. What's the goal here? Bubble habitats containing evaporating gases from ice-rich pockets on Mars, colonists eating mostly algae while hidden underground as a century-long project to make martian YBCO for an L1 electromagnet comes along? Sounds horrible and unrealistic even by bad sci-fi standards, but I'd guess doable on paper. Blue/Green Mars? Nah, that's likely some future heptillionaire's flex project. Less useful than the Aqueduct, more useful than funding statues in temples to Jupiter of the 8th millennium. But by that point, they'll rename Mars for McDonald's, the ancient Terran god of plenty and diabetes. Dunno what Musk did this time, but I'm guessing he promises self-sufficient Mars colony in the next 20 years or something equally stupid?