Why Didn't They ...

this is why I love this plot. they gave us just enough but not enough to have plot holes because we don't know whats going on 100miles down the road and what they have or havent tried in the past.

Moving your family to live by the river would require you to build a house ... by the river. Try doing that quietly. So living in a house that already exists, even though its away from the river, is probably a better move.