If there's a natural disaster cutting off electricity for days, trading bitcoin should be least of your worries really. Priorities man.
This made my mind laugh, which is basically true since it's already a serious disaster if electricity was cut for more than days. If you are talking about sudden electric shock which may cause your place to cut from electricity then I think it would be hard for you to trade without electricity specially if you are running loe of batteries, better to have generator at home that stores electricity when you will need it.