If you're in signal service for an update, you have alternatives. If you have no alternatives, you're out of range of updates. The sorts of devices involved (

If you're in signal service for an update, you have alternatives. If you have no alternatives, you're out of range of updates. The sorts of devices involved (and here I'm thinking of the GPSMAP series and friends) don't do over-the-air updates anyway, and don't rely on networked mapping services. Maps are stored on the device before you ever leave the house.