You will have power to spare as long as you don't try and run high usage gear, like a microwave or A/C. If you can go to making your coffee on the stove-top, you will be way ahead too. The biggest consumer outside of the aforementioned is the furnace fan. You may even have two furnaces. That fan motor is a thirsty critter. The only solution there is to not plan on leaving your furnace on over-night. Use blankets to be warm, otherwise...you'll wake up with no juice.
There is a good thread running on Inverters on this same C Forum, you might wish to find and read. Makes a good case for 12v gear and small inverters to charge the cel, computer, camera batteries.
Gary Haupt