It should be fine if you have the “it’s good enough” mindset and don’t mind things occasionally taking a bit longer to load while there are people streaming 4K content.

Try measuring the speed where you are planning to install the WiFi extender, devices connected to it will get half the speed

Geostationary orbit is at ~35,000 km. It’s far but the speed of light is “only” responsible for about half of the total latency