Will the family tree be intact when I move to another town?

I want to build up a save with my own Family Tree and I'm starting at Bridgeport and eventually want to move the decendants of my current sim to another town to get away from the hustle and bustle of the city.

When I someone, say the son or daughter to another town will the family tree be intact? And what would happen the family/sims left behind? Would they still be playable?