I'm sure they can take up to 10 degrees below their normal temperature for 1 day or so. Fish can go without food for quite some time, and don't worry about filter. When power is back, immediately 100% clean tank. They shouldn't die. And things happen, doesn't mean your a bad fish keeper. You just happened to leave town, which everyone does sometimes, and had bad luck. Bad things happen to good people.
By the way, that woman can get a neighbor to help her lift up the garage door, my dad lifts mine a lot.