Mine are teens now but I'm thinking back to their primary school days and I can't fathom how they'd manage with queuing for 13+ hours. Constantly moving, not able to sit down, cold through the night. I'm just in awe at the young kids who have done it. Mine would have been in tears I'm sure.
I think the longest we ever queued with them was at legoland. That was bad enough and there was an exciting ride at the end of it!