In my case, after pushing my car 2 hours in the desert i will loose the capability to drive up long dunes .
I have an obd monitor installed that allowes me to monitor the temp and other information recieved from the car ecu like The MAF and AfR , transmission temp and coolent temp. And what i noticed is that all the readings are not changing much during power loss episodes except the coolent temp increases from 77 to (between 95 to 108 °c i lose power) for the gauge in the dashboard this temp is still normal.
I think you should use a Bluetooth obd and monitor the temp live.
if you are facing this issue when temp is high then you will know where to look for a solution.
Thanks,