That limitation only counts for visiting other galaxies. Travel within the galaxy is always possible, regardless of the universe’s expansion. And Alpha Centauri is super close, even within our galaxy.
Dozens of dwarf galaxies, even! Also, Triangulum is sort of borderline at around 70% of the Milky Way's diameter, although admittedly only 10% of its mass. But Mars is also around 10% of Earth's mass, for a comparison.