LOL, that's a great observation!
Given the movement of stars within our galaxy and the size of the galaxy (about 100,000 light years across), it would be pointing at something completely different.
Today, it would be possible to compute it -- we should have enough information on at least the stars in the various constellations.
Yup. If we could see the Big Dipper as it looks right now it would very different - from earth we’re seeing how it looked a long,long time ago.