Using electron as a internet gateway for photons

[ScruffR]

@OBSteve

Is there a better / different way to do this?

I would use a 4G WiFi AP instead of the Electron and your 12V WiFi router and do the GPS stuff with another Photon (which also fits into the Asset Tracker Shield).
You'd just need to confirm that the WiFi capabilities (including inter device communication) are kept alive while the cellular network is inaccessable.