The art of battery sipping

[ShermanP]

Perhaps you missed chrisnightley's post in reply #3:

@chrisknightley

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.

So the pot would not be installed across the rails, but from a GPIO port to ground. Current would flow through the pot only when you need to measure the wiper voltage and you turn on the port, and that would take only a few microseconds once every second or so.

If the ATTiny85 can sleep pretty soundly with just one clock running for the periodic wakeups, the primary determinant of battery life will be what the radio needs. Everything else combined would average only a few microamps.