we live in a tornado prone area and of course when electricity goes out then no ATM card machines work. We're told to prepare the following ahead of time and store it where it can be reached quickly.
You plan ahead and you eat with a fork and spoon things like canned food (like meats, tunafish, beef jerky, vegetables, etc.). The heat will be off for cooking so choose precooked items you could eat cold. Or you buy things like crackers, canned juices, bottled water, trail mix.
Keep your car's gas tank full. When a person hears the warning they fill up their tank and fill up their red plastic liquid holder (you can buy that at Home Depot or any auto parts store, but you cannot store gasoline) if they plan to travel.
You're right, toilets will be unusable. If you feel the electric problem will be solved in a few days you can use a bucket with a tight lid or you can use your own toilet if you "tape" several layers of plastic bags so they won't fall in should the water come back and tape those to your toilet seat and go as usual.
Some people, who aren't in apartments, would buy grills that don't need electric, and heater or ac that would run on gasoline from the outdoors.
You can find a very long list of these things if you visit the Homeland Security website or a Florida website for tornado or hurricane safety. Sure cash is ok to have on hand but if there's no electric then the stores will be closed and your cash wouldn't be good for long.
If you're cold and the electric is out then emergency crews might be coming to your door to take you to some nearby stadium where you'll remain in a group until the emergency has passed.