Remember that if they are starting to get near capacity limits, they always have the option to make the antennas on the satellite larger, making the beams narrower, and reduce those 300 sq km cells down to say 30 sq km.

In the current era of phased array antenna prices falling sharply, and assuming they're willing to go for a folding antenna, I think they could probably easily get a 10x antenna area boost without much extra cost.