interstellar distance, especially at sub-light speeds?
Poul Anderson's Answers
In the Rustum History, political refugees from Earth colonize an extra-solar planet.
In the Kith History:
interstellar traders live in their ships;
one smaller ship visits a remote civilization.
In Harvest Of Stars and The Boat Of A Million Years, those dissatisfied with Solar civilization leave it.
In Tales Of The Flying Mountains, the motive is exploration. The Astrans will spend time at Alpha Centauri but might then either travel elsewhere or return to Sol. They will be equipped to colonize terrestroid planets although colonization is not their primary purpose.
Anderson as ever covers every option.