In S02E10 of Game of Thrones, after the men from the Greyjoy army stab Maester Luwin and flee, Bran & Rickon with Osha and Hodor come to Maester Luwin.
Why does Luwin want them to go to the wall and meet up with Jon? The Stark's allied forces were on their way. There was no Greyjoy army. So why didn't he want them to just wait outside the castle (castle was on fire) in someone's home till they come rather then sending them on a dangerous path to the wall. What was the danger for Bran and Rickon to stay at Winterfell?