Fun link. I was planning on similar setup using a couple of remote linked Celestron C8s separated by 5 miles to observe thunderhead cloud formation in SW Florida. Average natural IPD is around 64mm so it should be interesting to see what the occipital lobe does when this is expanded to over 8km. (IPD = InterPupillary Distance; eyeball separation)

IPD?

Interpupillary distance, the distance between the centre of the pupil in one eye to the other.

Stellar parallax is virtually unnoticeable even when the Earth is on opposite sides of the Sun (~300M km apart), so I don't think the stars would look much differet even if you doubled or tripled that distance.

Objects inside of our own solar system, on the other hand, would be really interesting to look at through such a setup.

Just a nitpick, but how could one see the tops of clouds when the two cameras are only negligibly above ground level?

In the flat FL interior during hot summer days with no wind it's common to observe distinct long wide columns of clouds form anvil tops over the space of a few hours in the early afternoon. Sometimes, if you're lucky, a cauldron shape will form which puts on an impressive light show at night. Rather than risking a light Cessna it might be interesting to view formation in exaggerated 3D from the ground.