My cousin and her family (4 children...9,8,6,2) live in England.
Until the older girls were school age they split time living in US and England. her husband's business is in both England and US. He comes here more often but they still all come around Feb and stay 6 weeks.
Her girls are not "excused", but she has the school work that is to be covered and done when they get back. They also do some sort of report on what they are doing in the US.
I also substitute teach and there is a family in my neighborhood with 4 children from Columbia. Their dad is a professional soccer player here. In Dec, we give assignments to those children and they are gone about 6 weeks as well, however, winter break is part of the time they are gone.
Hope that helps.