I have a customer interested in using the IoT sensors in their refrigerated truck deliveries. The deliveries start at the distribution centre but could be delivered to any of their stores. They would like to be able to track the temperature from preparation to final delivery. The IoT sensors seem to have a reasonable amount of "offline" storage making them suitable for use in vehicles.
So that's another use case for being able to decouple an IoT sensor from a specific networks base station.
In their case, I see all the IoT sensors being in a single network, and their food safety people being given only access to that network.