you should spend some time looking at how you will power a small fridge. They use a LOT of power..
I dont know about really small ones but something like this http://www.amazon.com/43-Portable-Compa ... B0012EGZ9S
is what is commonly used on a sailboat (if you have to have a fridge) and this type with the compressor is supposed to be the most efficient. But these still use between 35 to 50 amp*hours at 12 volts per day. It usually takes at least a 100 watt solar panel with good sun to keep this running and it also takes a lot of battery capacity maybe on the order of 200 amp*hour and an alternate charging source in case of some days with poor solar.
I dont know what is out there that scales down for use on a TI.. but I think if you pick something out, make sure you figure out how your going to power it - and I think you will likely find the compromises you have to make to keep that thing powered are just not worth it.
I am also of the opinion that you should figure out how to use ice and if you cant get ice, figure out how to get by with out the need for the cold storage.
edit.. I looked at the links posted earlier. The two cheap ice coolers dont even list the current they use. The more expensive cooler say is uses 4 amps. The lithium battery that comes with it is 16000 mAH or 16 amp*hour. So that lithium battery will run that cooler for about 4 hours, then its depleted. I would assume the very cheap coolers use on the same order of current.