Only 3 castled are manned according to Jon back when he was with the Wildlings. We know Castle Black, Eastwatch and the Shadow Tower. And Janos was going to be sent to abandoned Greyguard when he refused. I guess they'll be doing a lot of walking to get to the first castle and hope they can get down.When someone dies in this show, you see them die. So I don't think Berric and Tormund are dead, either. They've got a lot of running to do on top of the wall to get back to civilization, though. I don't know how many castles in the show are actually manned, but the nearest one has got to be at least 20 miles away - if it's still in good shape, they may be able to get down from the wall. Castle Black is probably 150 miles away (the Wall is said to be 300 miles long).