I've been through countless power outages, including 2 that lasted a week each.
For an emergency toilet, you can buy a toilet seat that fits on a 5 gallon bucket. I keep a bucket and seat with a pack of dry RV holding tank chemicals stored in it.
Battery powered lights are handy, but expensive to run for a long time. I keep 4 filled oil lamps in my house, have used them more than once. You won't read a book by one, but you can find the toilet with one.
If you've ever been thru a power outage without a means to cook, you'll pick up a dual-burner Coleman stove at the next opportunity. If you like real coffee, an old-fashioned stove top percolator pot is wonderful.
Liquid-fuel Coleman lanterns put out a lot more light than an oil lamp, and they put out significant heat also.
If you're forced into combustion heating and cooking indoors, be sure to crack a window for combustion air. Don't go to sleep in a room with a combustion heater that doesn't have an oxygen-depletion sensor on it.
An old rule of thumb says that, for lighting, propane is 4 times more expensive than liquid fuels, and batteries 4 times more expensive than propane. For a long-term outage, and you won't know if it's going to long-term until it's over, you should gravitate towards more liquid-fueled appliances and fewer battery and propane.