While the process documented mirrors the process for traditional
> landline phones, it doesn't address what happens when the VoIP user
> takes their phone someplace else and then calls 9-1-1. Which center
> is called? The one for their home of record or the one serving the
> hotel/motel/grandma's house?
The one of record, of course.
However, if they can get a quick and easy way to update your address (preferably with scheduled changes in advance -- So that I can enter my travel itinerary in advance), it should smooth the whole "VoIP adapter isn't at home today" problem.