So no flying off to tera form other planets huh? Or will there be enough time to get some people in orbit?
I suppose it might take a few years, for the Earth to be consumed, or just shrink and suffer enough tectonic disruption to become uninhabitable. Assuming the wars of nihilism and panic, riots, suicides etc. didn't make it impossible, perhaps some kind of international crash program could make some kind of station, stocked with supplies to keep mining the Moon, Mars, Asteroids, comets etc. for supplies and consumables, plants, animals, and sufficient genetic diversity of people.
Although, a small black hole just the mass of Earth would probably be very dangerous just from the incidental x-rays from solar wind, micrometeorites, dust, etc. that it would be sucking up. Anything near the orbit of the former Earth might be too dangerous. Or it's orbital dynamics could change, and if it fell closer to the sun, really blast the whole solar system from it's accretion disk of solar material. Nowhere would be safe out to the orbit of the outer gas giant planets.