Signal Boosting for underground electron

I’ve got a project where a 2G electron will be running some data collection in essentially a 50ft deep open top pit. I’ve tested on location and can connect to the network but very intermittently, only connected about 10% of the time.
Has anyone had any success using a cellular signal booster? Something like:
with an external antenna that I can mount above ground level and bring down to the electron. Or is there another way to improve my connectivity?

If location is relevant, the project’s in southern ontario (canada).

Using this code to monitor connection events with an extra “Particle.publish(CONNECTION_EVENT_NAME, “testing”, PRIVATE);” every 2 minutes.

Separate the electron from the sensors, maybe have an Arduino/NodeMCU and a link between the two with the electron located up top …

Logistical access to the top leads me to prefer a solution that can be installed and left like an antenna as opposed to the electron that I may need to physically access in an emergency/hardware failure. Also there’s two electrons down there so i was hoping a signal booster would allow both of them to connect. 1 booster as opposed to 2 new MCUs + re-testing all the code already written on the particle.
Even if I did use that method wouldn’t there be concerns with capacitance and resistive losses on low voltage signals on long wires?

Depnds how you link them, but RS485 is excellent over distances way longer than that, why 2 electrons in one spot?

there’s two unique, modular, systems being controlled and data logged for comparison. Available space is limited so they are set up beside one another.