Shouldn't take too long. I imagine within 2 chancellorships, it is entirely possible to reclaim all the lost territories, if no restrictions are set for conquest.

Also, being part of the family doesn't mean you will get married. Most of the current characters (and the recently deceased) were bachelors all their lives and some (like Arnold) still haven't been married. Hans only got married the turn he got himself killed, so that's almost a hundred turns since he's been in play.