Can you share the set up w/o cell service needed?
So the setup would be exactly the same at the camera side but would remove the MiFi X Pro 5G and add a UBNT NanoStation 5 AC Loco to the box mounted on the outside with line of sight back to the firing line and a 12v to 24v POE converter to power the Nanostation....I then use a larger LiPo battery than the 6000mAH like the car jumper pack batteries run for 6-8hr... something like a 26800mAH battery pack..
Ubiquiti NanoStation 5AC Loco, 5 GHz airMAX ac CPE with Dedicated Wi-Fi Management (Loco5AC-US)
https://a.co/d/0Qmrot0
Tycon Systems DC to DC Converter, 12VDC Input Voltage 24VDC Output Voltage, 19W Maximum Output Power (TP-DCDC-1224)
https://a.co/d/04jGIB6
BUTURE 5000A Car Battery Jump Starter (All Gas/10L Diesel) Smart Portable Car Jump Starter Battery Pack, 12V Safe Jump Box Car Jumper Starter with Extended Jumper Cables, Fast Charge, 160W DC, Lights
https://a.co/d/3Q5e6D8
Then at the firing line, you need the same setup at the target mentioned above minus the camera....then you could plug a Lan cable into a laptop and see live.... OR what I do is add a cheaper WiFi AP to the setup at the firing line then you can just open the camera app on your phone or tablet with your phone connected to the WiFi network you setup in the AP...
Works like this..
Camera is powered by the 12v -48V poe injector, sends HD POE IP video to the NanoStation via the 12v-24V injector and wireless beams it back to the firing line where the receiving 2nd NanoStation grabs it... you can then either use an etherner cable in a laptop to see the camera on your laptop software or shoot that signal into the air via a wifi AP and use the same app on your phone or tablet to see the video.. these NanoStations have line of sight distance capabilities to 5km+
Beauty with this setup is you can have multiple cameras down range at multiple targets and beam them all back to the single receiving NanoStation at the firing line and see all the cameras in your app.... love using nanostations because you can do point to Point or point to multi point....