We've done it in the past for our early-mid May trips with no issue when the boys were in elementary/middle school. Both boys are bright and in the case of my eldest who doesn't do well with standard, daily homework assignments due to learning disabilities, teachers were eager to have an excuse to assess him on longer-term, independent projects.
Now that the eldest is in high school we've been less willing only because this school is less forgiving about missing lectures and tests. However, because he opted out of our last trip (at the end of his freshman year) we're planning to take them both out this November on a big family trip to celebrate their birthdays (the 16th and 21st turning 12 and 18 respectively), some major accomplishments and personal growth for all of us (like my husband and I finding work after a long drought) as well as celebrate my FIL coming back to health after a stroke.
Knowing that my eldest has been able to make connections to art schools that want him and his grades are stabilizing helps. Also, while his school is unforgiving about missing tests, they never give tests the week before Thanksgiving because most of his school (very rich kids) are on vacations during that time anyway. My youngest is in leadership positions in his school and involved with quite a few clubs and has proven his ability to keep up with work despite the extra-curriculars. We had considered taking them out in early December when the prices and crowds are a bit low, but we know both schools make a push for finals during that time and our youngest will likely have end of semester concerts and plays scheduled too.
ultimately, you have to do what's right for your own kid and your own family. A school will always say that they want the kids in class, although some of that is self-protection since attendance rates can mean a lot for funding and accountability purposes. I am also quite sympathetic to the extra time and work this may create for teachers. However, I've found that fostering a good relationship with the school, the teachers and the administration helps. At this point both school admins know a lot about what our family has been through in the past few years and one actually applauded our decision to take a vacation to celebrate. So, I'm hopeful that any problems will be resolved painlessly.
That said, this year we're going to be planning a "work then play" day as part of our vacation. We'll play for a few days, taking breaks during the day to write up some notes of what we did, etc and then plan a day where we stay at the hotel and get caught up on assigned projects and homework, so we aren't scrambling at the last minute to finish all of this. If they get it done, they get a special reward.
