Into The Oort is set in a region of space that is 50,000 astronomical units (AUs) from the Sun, way out where the comets that orbit the Solar System move in a vast shell across a huge region of space. What is an AU? An AU is the distance from the Earth to the Sun. Which is vast. To reflect the incredible distances and emptiness of space, each hex is 10AU across. Approximately 1.5 billion kilometres. If you were moving at the speed of light it would take over an hour to cross a hex.
A hex is big.
As with other settings, a hex in the Oort has a quality to it. In another game it might be called the "terrain". Some are basically space, empty; some have dust clouds, some have a high gas concentration, some have cometary debris, some have rogue asteroids in them. With the distances involved, there is a good chance that there is a human settlement of some form somewhere in a hex; if not, there is a good chance that there is an old human settlement - something abandoned or lost or wrecked. And of course there are ships that are travelling here and there; the Oort Cloud is big but the people living there are not static.
Occupied settlements might have huge populaces - tens of thousands of people - or only have a few dozen, or even less. The Hub - the largest human settlement that anyone knows about - has far more people than anywhere else, and no-one knows quite how many people live there.
The region of the Oort Cloud 50,000AU has, from a back of an envelope calculation, on the order of 500 million hexes. If, on average, each hex has a thousand people in it (some have far more, some have far less) then this region of the Solar System might have 500 billion people living in it.
Variety and wonders and opportunities are everywhere...
A note: for the playtest campaign and ultimately a release of Into The Oort I am planning to populate a region of around 50 hexes around the Hub, along with tables for populating hexes with settlements, groups and people. I've shared an in-progress document for generating the basic outline of a human habitat before; if you haven't seen it you can get it here.