If you want to make a really dramatic movie, have it survive in giant rock fragments knocked into orbit around the sun when the Chicxulub meteor struck the Eart

If you want to make a really dramatic movie, have it survive in giant rock fragments knocked into orbit around the sun when the Chicxulub meteor struck the Earth. The inside would hopefully remain very cold and shielded from external radation. I suspect though that not only would breakdown of DNA still happen on it's own, but atomic decay within the rock would be enough to destroy the DNA.