I have laxed on getting anything...and considering I live in an area that should be prone to outages I should be concerned but I am like magyver so I would whip something up...
Best bet for short term.a ups to your powerheads and a air pump just to keep things living.
For longer term...cant beat a generator...you can buy a cheap one at harbor freight for like $200 bucks when they are on sale. install a plug on the panel and you can feed your whole house (running minimal things of course, fridge, a light, your tank)
And of course home depot rents them but you can bet in a major outage your local one aint going to have any left
and of course the cheapest way to go grab an inverter hook it to your car and start her up...(I would call this a desperate last act in a long term outage) but a route nonetheless