With rolling blackouts/brownouts, and the top Energy users being asked to cut usage, several cell sites are down (rotating). When your phone is farther away from a cell site, it boosts its transmission power to compensate, running the battery down faster. Analogue usage is 5 to 10x less than full strength digital usage. "Consult User Manual for Details".
Specific to Rogers, if your phone is TDMA, you have analogue backup as part of the hardware. If your phone is one of the newer GSM models (and this applies to Fido as well) you have NO analogue backup, and go from "digital signal" to "no signal", and drop the call.