Depends on the age of the children.
My DD is 10, so in year 5. This week, only four days as it's the start of the school holidays, had maths, English, PE, science, topic work, guided reading and writing, music and art. I've probably missed something.
You think primary kids do a 'bit of English and Maths' and yet you ask what they do in the space of a week? I know from volunteering in a reception class for three years previously, that they learn an awful lot. The pace of learning is fast and things are not revisited in depth but the skills they learn are used further down the line.
My DD missed one day of school recently and the homework for Maths last week was covered on the day she missed (due to a hospital appointment) and now she has no idea how to do the homework she's been given.
I do think that if you can't stick to the rules or put the same effort into your children's schooling then home educate. You can either leave your dc at home with your dh while you go abroad or you can time your trips to fall into the 13 weeks of holidays they get each year.
But I'd advise against railing against the system before you are even in it. And I'd be interested to know how you'd facilitate your dc's learning when they reach exam level.