Well , its starting to snow here in NJ , so it's probably too late for you to do anything substantial , like a UPS or battery backup to run your heater/filter .
If you can keep your place in the low 60's with the stove , you'll probably be OK if the outage is short . If your tank is decent size it'll have enough thermal mass to lose heat relatively slowly and you'll be good .The fish will take gradual changes pretty well. If it's a long outage , and you can heat water on your stove , maybe putting some water in a plastic bag , sorta like a water balloon , and heat the bag in a pot of water until the bagged water is slightly warm , and then float the bag , keeping it away from contacting the tank sides , maybe the heated water in the bag would heat the tank sufficiently . Have to keep an eye on the tank temp. when your doing this though .
Just as an aside , I was out for 9 days after Sandy . I've got a generator tied into my house via a transfer switch , but it only runs a few necessary circuits , so my fish had no light , filtration , and water temps were in the low/mid 60's .
I fed once about 4 days in , gave 'em a few hours of poor light via extension cords . No losses , plants were fine ( I have mostly low light stuff).