- Have you thought about include another battery and measure the impact in the autonomy ? It must duplicate it, doesn't it?
I'm thinking too in a temperature logger. I guess a temperature sensor will consume less power than a gps so the autonomy with two of those batteries could increase to a few days
What's the point of the CR1220 battery? are there a realtime clock? or it's used for another reason?
Which GPS module has been used for your project?