I think genetics is actually the easy part. A few dozen or so people, selected for strong health, probably contain enough genetic material in their groins to start a colony. More would doubtlessly be better, but I think such things have been done by humans on earth before. Frozen eggs/sperm and women willing to be surrogate mothers help a lot too; you wouldn't need artificial womb technology, necessarily.

The hard part I think is "playing factorio IRL" on a planet we weren't evolved to cope with. Bootstrapping industry sufficient even to create additional shelters would be very challenging. Maybe we could practice this on Mars.