I'd probably take my chances on the planet rather than on a rush-job interstellar mission. My totally unquantified intuition is that the perturbation caused by

I'd probably take my chances on the planet rather than on a rush-job interstellar mission. My totally unquantified intuition is that the perturbation caused by the black hole arriving in the system is more likely to eject the planet into interstellar space than to cause it to intersect with either the star or the black hole. Even on an icy sunless de-atmosphered rock I think survival would be possible, living off the internal heat of the planet. The planet would become the interstellar mission.