So possible approximate calculation if you are saying total up time is 14s
14s @ 80mA = 1120mA
300s X 98% (deepSleep actual time) X 0.040ma = 12mA
Total mA 1132 every 308 (14 + 300 - 6) seconds. So average consumption rate is 3.7mA
For a 3400 mAh battery the Digi-Key battery life calculator at https://www.digikey.ca/en/resources/conversion-calculators/conversion-calculator-battery-life gives 643 hours approx 27 days.
If the 14s was as long as 16s due to WiFi connection sometimes being 6s not 3s then it’s approx 24 days.
So it’s broadly similar to your actual result.
Taking a 5s uptime and a real 10 minute sleep (10.2 deepSleep) it would be:
5s @ 80mA = 400mA
600s @ 0.04mA = 2.4mA
Total mA 402.4 every 605s, average consumption rate down to 0.67mA (3552 hours, 148 days).
The huge improvement is primarily down to the much lower up time, down time changes are not too important at the negligible mA involved.
I would probably factor in a further 50% reduction for the 148 days down to 74 days because I know from experience that I never achieve anywhere near calculated rates.