Personally, I am working toward setting up an alternative energy system for my home, utilizing solar and possibly micro-hydro to feed electricity into a bank of deep-cycle batteries that I will draw my power from in an emergency. Conversion will be achieved through the use of an inverter. It won't be a large system, just enough to power a chest freezer, refrigerator, and charge batteries.
But what if the situation or emergency warrants that you spend a day or two in your basement or shelter away from your convenient appliances? There is an option that would still allow you to preserve some things and take them with you. With this option, you would utilize a moderately large ice chest/cooler such as this one:
Your perishables would be placed inside along with as much ice as you can scrounge, and periodically you would replenish the melting ice with new made using one of these:
And, you could power the ice maker using a rig like this one:
A quick Google search reveals that the portable ice maker consumes 400 watts of electricity at 3.5 amps and 115 volts and it is capable of making 35 pounds of ice per day. Also, the Xantrex Powerpack 1500 now ships with a 51 amp-hour battery (not 60ah as stated by Amazon or 63ah as stated in the downloadable owner's manual).
So, unless my math is even worse than I think, that means if your Powerpack has a fully-charged battery you could run the little ice maker for approximately 14 consecutive hours (better to spread the time out though) and make almost 1.5 pounds of ice per each of those hours to supplement your cooler. Using these methods and running the ice maker say five times per day for an hour at a time, you could stay inside your shelter and keep your cooler's contents cold for at least 3 days before the Powerpack battery was drained.
Ideally, though, your best bet would be to pack the cooler with things like cold cuts and fruit as they will last longer in a refrigerator but wouldn't require so much ice, thereby freeing up some of your battery's amp-hours to allow you to run lights and a radio in your hidey-hole. As always, it's good to have more than one option. I hope this helps.