What would be a good cheap efficient model/brand if you only cared about keeping the freezer running? I’d alternate power between the freezer and fridge until the fridge was empty. Also, switch it over to the microwave for quick meal cooking. From charts, the microwave pulls the most 925 watts, a fridge at 725, and freezer at 600. Order of need is #1 fuel efficiency, #2 cost, #3 ease of maintenance and reliability over the long haul and #4 noise.
A big plasma tv during any outage wouldn’t even make it onto my list.
Honda makes small generators too. I think as small as 800 watts. I see them all the time at the dog shows. They use them to run blow dryers. I would check into one of those. You also may be able to pick up a used Honda on Craigslist if you are patient.