I am also a teacher and have gone at summer and Spring Break. Spring break was a lot more crowded than the 2nd week of June, still, with our unofficial guide and fastpass we had no problems. I am optimistic about this Christmas trip. We are hoping the crowds will be minimal until around the 23rd.........we are taking that as our off day. We're doing Epcot on the 24th because it's the park that can absorb the most people. But, the 25th was left to the children to decide, so we will be in MK.............even though I know we shouldn't! So, I built in a day and two evenings at MK earlier in the week so that whatever we do on the 25th will be extra and not "must do".
So close now!