NVCHUKAR
WKR
Read this article, has a lot of useful tips. You should be able to keep a cooler with ice for a week if packed full of block, left closed and out of the sun.
http://www.rokslide.com/2012-01-09-05-09-42/essentials
http://www.rokslide.com/2012-01-09-05-09-42/essentials