Once SpaceX's StarLink constellation is fully deployed (i.e. Polar orbits as well as the initial lower inclination ones), this should be a piece of cake without violating any terms of service.
Iridium's (and SpaceX's future Starlink) constellation is unique in that it is in LEO and uses intersatellite links. That means it works everywhere, including Antarctica. NSF's local network is connected via a bunch of Iridium radios at great cost. Other constellations like GlobalStar's and OneWeb's are bent-pipe designs, essentially just repeaters that rely on nearby ground stations. They don't work too well in Antarctica or far out to sea.
I'm not sure there's any realistic way to do this.
Triangles would be HUGE
I played a few years back, just by bike. But players in cars would always be quick enough to take down what I built.
As a rural player that lives in the city nowadays, I don't even feel remotely interested anymore as you can't impact the scores as much as you can in a rural area.
Pokemon egg hatching took this to a new level.
(p.s. you don't think Google aren't using Ingress to gather data?)
I think it's also worth mentioning for context that Niantic is not owned by Google anymore, though Google is a major investor still.