“And all the stars a stage” (1971) by James Blish is another one where human-like aliens escape the destruction of their home world in 30 ships just to wander the galaxy looking for a new home, running into one disaster after another as their attempts to settle on various worlds end in failure and lives lost, until they happen upon a tiny, blue-green world with the most hospitable climate imaginable… with only one ship and a handful of survivors left.
It’s a poignant story of endlings, and the extinction of one species at the civilizational dawn of another.