News Starlink touts $9 a month 5GB data cap plan to Australian users — marketed as a 'Backup' option

How do you roam from a satellite?
Some plans allow it to be used anywhere on the planet, others are expecting you to be in a fixed location like your home. Though I think it's actually a zone that could be as large as a town/city, so you could relocate it easily.

If too many users are in one location at the same time, they could experience degraded service because the handful of satellites that are in range overhead would be servicing tens/hundreds of thousands of people at once. This is why Starlink is not the best solution for dense cities (where everyone ought to be getting multi-gigabit optical fiber anyway).