Even if you use a comparator, I feel that it is difficult to detect that the POT has rotated.
This is because it is necessary to retain the "previously transmitted voltage".
Probably, I think that I will wake up from sleep on a regular basis, acquire the POT value with the ADC, check if it has changed from the value acquired last time transmitted it, and if changed then need transmit it.
In that case, the current consumed by the POT can be reduced by connecting the POT to the port instead of VCC and passing the current only when measuring with the ADC.
Batteries larger than coin batteries may be required depending on the polling intervals required.
I'm sure it 2032 