UP - to be 'safe', wait 3 weeks before you lift the rest & then put them in your tin!
Chris - too tall, man - too tall! Don't know, but I would cut the tall ones down to just above the second or third leaf up. And since you have no room to earth up, make it by putting 5-6" ply (?) slats in around the 4 sides.
And put in full light until the frosts.