Oh wow, that sounds like a lot of fun!
I wish my family did that, the whole two weeks at a Disney park. I was lucky if I got to go once a year to Disneyland. But now it has all changed, because we moved, so it less likely that I'll get to go because I live SO far away.
But I like your family's idea of going for two weeks every few years.
Make sure to take lots of pictures! And post all the ones without people on here.
Don't forget your VMK quests, too!
Have an AWESOME TIME!