I used to take my two girls out, and we never had any issues in elementary school. The issues for them started when they had to take finals. If they were absent a certain number of days, they couldn't exempt them. Believe it or not, they get to the point where they'd rather forego a trip to WDW, than take their finals.
I used to have our trips planned before school even started, and I'd mention it to the teachers at the first open house. I'd suggest that they give my girls an extra assignment to complete while they were gone (a report on a country in EPCOT, for example), but they never took me up on it.
We always left the day after Thanksgiving, so the teachers always sent home the next week's work, before the Thanksgiving holiday started. Both of my girls had no problems completing it before we left. I'd get a neighbor's kid to deliver it to the school on the following Monday. That way when we returned, all they had left to do was complete homework, and take exams, and the teacher wasn't hit with a week's worth of work to grade all at once.
Fast forward a few years and a new husband

laughing

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This brings me to my step-daughter. She's only 9, but in a different school district. When I asked her teacher, I was told that she could be gone, but when she returned she'd only receive 50% of her grades. So, even if she made 100's on every paper, she'd still get a failing grade for the whole week.
That put the end to that thought! That's why we went Spring Break in '06, and the first week of June in '07.