In Octave, is there a way to persist data on the device between reboots without relying on cell service?

Our concern is that the device will boot, but not be able to find signal. In this case, we still want to record our location for future transmission, but then go back to sleep rather than draining the battery constantly searching for a connection.

Yes, the persistence settings in store and forward control this. You can configure how often the device will save data so that it will survive a reboot in the event it can’t be forwarded to the cloud immediately.