For an isotropic emitter (omni-directional) the inverse square law tells us that power is reduced by taking the reciprocal of the square of the change in distance. So doubling your distance from the source would get you 1/4 of the original power. Unfortunately cell tower radiators are rarely isotropic. They usually use high gain directional antennas. For some light reading you can reference this document ...
Cell Tower Radiation Report
You are correct, there are contributing factors but these are most important when it comes to desense or receiver front end overload.
1. Interfering Antenna Radiation Pattern.
2. Interfering Transmitter power
3. AC/RC Receiver Front End Bandwidth
You might be able to fly with impunity above or below the directional lobes of the typical cell tower, but get close enough and in the highest power lobe and you might lose control. It's somewhat like trying to see at night when you have oncoming traffic with their high beams on.
The DJI frequency specs for the
Mavic 2 are:
2.400 - 2.483 GHz
5.725 - 5.850 GHz
The 2.4GHz channel could be sensitive to some current 4g/LTE bands. The 5.7-5.8GHz channel should provide better immunity.