Long-winded reply...sorry.
Boardwalk Tigger, you think my in-laws are pains--you haven't met my kids!

We had originally planned on bringing all our kids to WDW the end of January when they had (operative word--had) a 4 day weekend. The school district then decided to have school one of those in-service days, so it would have meant loosing a day off.
The real kicker, though, was last spring vacation. We went to Universal to use the tail-end of our APs (we'd gone the year before with our kids at the beginning of the AP). While we were at Universal, our 16yo daughter informed us that nobody had asked her what SHE wanted to do for vacation and that she'd rather be at home with her friends. Hmmm, didn't make me want to vacation with her in the future. lol Not to mention the fact that half of her senior year will be college classes--not just AP, but a program where a commumity college holds actual classes with professors at her high school.
Then our soon to be 14yo just started high school and has some minor health problems that make keeping up in school a challenge, so now that unexcused absences can affect his high school GPA we need to think long and hard about him missing.
I will be bringing my 10yo in January, though, which sent the older siblings into fits of jealousy. And then I'll be taking my 4yo down in December to meet my mom and sister.
And the most important reason??? My DH and I need to get away!!! The two of us haven't been away for over 6 years, and that was only for one night. The time before that was 15 years ago.

Need to get away...
T&B