All galaxies currently beyond 18 billion light-years are forever unreachable by us, no matter how much time passes.

Beyond distances of ~14.5 billion light-years, space’s expansion pushes galaxies away faster than light can travel.

All galaxies beyond a certain distance always remain unreachable, even at the speed of light.

The final ones, in the M81 group, will become unreachable after another ~100 billion years.