I think you've vastly underestimated the difficulty and the timeline, ironically. It's unrealistic to use the words "decades" or "a century". On the contrary, that's the delusion.
Consider: more than 50 years after putting a few people on the Moon very briefly, we're no closer to a colony on the Moon. And rocket technology won't help at all. Among the problems: the Moon has very little gravity, and we can't handwave like Q, "just change the gravitational constant of the universe."