Here at McMurdo we've had 24/7 satellite internet for at least as long as I've been coming down (~10 years). Think roughly a ~30mbps connection shared with ~1000 people with business and science bandwidth prioritized over personal browsing. So starlink has been a game changer for sure.

At South Pole, I believe they don't yet have access to starlink. They also don't have 24 hour coverage for the few internet satellites they do get.

I don't work in IT so don't have direct access to more specific information, and obviously I can't speak for the many other stations scattered throughout the continent.