Last July we started out our morning with hubby determined to get us on Nemo, when the gates opened he rushed to get in line while I tried to get a stroller and meet him there asap. But really even though we waited 2 hours in the line it did move fairly quickly and I think the best advice I can give is to be friendly with the people around you in line. When my youngest started getting antsy hubby took him outta line, fed him nearby at TT then he got back in, nobody seemed bothered because everyone was getting hungry and hot by the time we got half way. People were offering to hold a neighbors spot while they go grab a bite, or use the bathroom. So I think stepping out line for a potty break, grabbing a bite, etc is o-k. As a mom I'd completely understand if you're dh took the kids out of line for a quick break and then brought them back. Good luck 
