My battery might supply 3.7 V, while absolute maximum for an IC it is supplying is 3.55 V and lowest operating voltage is 2.65 V. The IC is at sleep most of the time, consuming 10 nA. Every now and then <1 % of it's lifetime it wakes up to consume 1 mA. Voltage could be dropped with a series (Schottky) diode. Here are curves for I-V curves for forward currents at different temperatures from Toshiba CUS10S30 Schottky diode datasheet:
But only if it was always 25 C and current draw would be stable. I do need to make a sacrifice to one way or the other, but adding an LDO regulator type of a device would drain the battery fast. How do I achieve not damaging the IC and only sacrificing ~tens of % of battery life?