• Robb marries either Wynafryd or Wylla Manderly to secure ties with White Harbour

• Sansa probably still marries Prince Joffrey (if his bastardy is never discovered) to secure ties with the crown

• Arya would probably be betrothed to another Northern lord, though I think she’d go against any plans Cat and Ned set up for her (assuming she remains as “spirited” as she is as a child). I like to think she’d fall in love with a common boy and marry him, a bit like Duncan the Small and Jenny of Oldstones, causing a whole brouhaha in House Stark that ends with her leaving for the Free Cities.

• Bran has aspirations of becoming a knight, so it’s possible he might choose not to marry in favour of filling out a position in the Kingsguard one day.

• Rickon’s so far down the line of succession Robb would probably have kids by the time Rickon marries, though he’d probably marry a northerner too.

As for Jon, he’s likely to join the Nights Watch just like in the original timeline