Every year in the mountains near me, they have local power outages. These can occur at anytime of the year, but are more common in the winter. Cell phones aren’t reliable in many areas, due to the terrain. It seems like every year I encounter someone who has had their landline phones fail during a power outage. Every time I encounter this, I check to see why the power outage caused phone failure.
Ninety-five percent of the time, it is the type of phone that the person owns. The other 5 percent is downed phone lines. The phone lines provide the electrical power to operate older style phones. The problem is with wireless portable phones that require normal household electrical current to function. The phone lines provide a much lower current than your household power. The simple rule is, if you have to plug your phone into your homes electrical system, it will not work during a power outage.
Get an old-fashioned phone, you can find them cheap in garage sales all the time. They will operate off the electrical power supplied by the phone company. The phone company keeps battery backup and generators for this purpose. This will not last indefinitely during a large prolonged blackout, but for local interruptions, you can often avoid power outage caused phone failure.
I personally feel that as the infrastructure continues to deterioration, intermittent power failures will become more common. Getting an old phone will not solve all your communication problems but it will be one more tool in your kit.