It would be lovely to homeschool according to the laws of one’s “official state of residence” - but it doesn’t work that way. Kids are to be educated where they reside at the time or according to the laws of the state in which they currently reside.
In your argument, no serving member of Congress is s resident of the state he represents
I do not know the tax code and how it treats the families of those who temporarily locate to DC while serving in Congress. I do know that Santorum paid PA state taxes and maintained an abode in PA and was for all tax purposes, a PA resident.
>>Kids are to be educated where they reside at the time or according to the laws of the state in which they currently reside.<<
So what if you have two residences in two different states?