I would guess that it woulddepends on the local economy. If a loaf of bread is worth $1 of a local fiat currency, and the local exchange rate for BTC is about $1=0.000015BTC, then I'd guess that you might be able to get about 3-5 days if you're frugal. It also depends on the buying power of your local fiat. For example, USD will get you more BTC per dollar than the Philippino Peso. 

 So you are saying I am screwed no matter what.  

 Well, I'm not sure of your situation. If you want to explain it a bit more, I could do a few napkin calculations. 

 i am half kidding, because i am dealing with a big issue at the moment, and it is kind of overwhelming to say the least. i appreciate your thoughts. also i am going to start using that phrase "napkin calculations". super adorable.