Our population is already bumping into a logistic growth ceiling. Earth's limited resources can only support so much.

Settling our moon, Mars and the Main Belt would likely push back hitting the ceiling for a few centuries or millennia.

After the Main Belt there are the Sun Jupiter Trojans as well as the moons of our gas giants.

And then there is the Kuiper Belt and Oort cloud. If we successfully harness fusion energy this may be usable real estate. The sun is no longer a practical energy source this far out. This would postpone bumping into the logistic ceiling for millennia.

Oort cloud bodies are quite far away from one another. Early space settlements in the inner solar system could rely on earth and neighbors to help each other. But as we expand outward the islands nations will be more distant from one another. Getting help from neighbors is less doable.

Outer Oort nations will need to be self sufficient.

It is thought many Oort bodies have lots of water ice. This plus fusion would enable an island Oort nation to move. And I expect some would want to move away from the solar system.

The day dream I like to entertain are Oort nations gradually drifting into interstellar space. And over millennia reaching the Oort clouds of neighboring stars.