How long will it take for interstellar migration to come true?

Besides, 1000 years. Let's talk about the destination of immigrants first. At present, there are two feasible goals.

The first is to transform Mars, which is very close and has its own atmosphere. At present, many feasible experiments to transform Mars are under way.

The second one is Earth 2.0, that is, kepler-452b, which is the nearest planet discovered by human beings at present, but it is more than 1400 light years away from the Earth. Unless human beings can make a breakthrough in cryonics or the speed of spacecraft, we can only see through telescopes.