Having lived for many years in various assorted versions of "electricity goes out" country (blizzards, ice storms, hurricanes, earthquakes, third-world unreliable electricity), here's a tip. When the electricity goes out, I'm sure everyone knows not to open your freezer in the hopes that perhaps the power will come back on before everything thaws. Sometimes, when it's bad enough, we leave town until the worst is over. When we come back, it's basically impossible to know if perhaps everything thawed, but refroze.
Pre-outage, freeze some water in a small cup or glass. When it's frozen, put a penny on top of the ice. Then, when power comes back on, you can tell if it thawed enough for the penny to drop to the bottom of the glass.
