I picked it up at Cabela's the last time I was in the US. I think they still sell them. About 20 bucks. I waterproofed mine with Nikwax tent and gear proofer...the buckle tighteners have a funny design and since I've waterproofed it, they slip really badly. The tub and top flaps are waterproof anyhow so waterproofing isn't completely needed. I just didn't want the canvas to take on water and rot.

Thanks for all the tips. I haven't had an issue with the jug so far this winter but as opposed to risking it I've decided that I'm going to put a flat of bottled water from Costco in the back. I did this on my last road trip with great success as extra water for drinking and cooking. Easier to carry a bit at a time if needs be as well (or split up between several passengers). I'll have to keep an eye out at the local surplus shops for a proper shovel. The Coghlan's shovel has never been used as I usually use my Gerber folding shovel for digging.

Food is something I've been going back and forth on. I bought some Mainstay rations from BestGlide a while ago but unfortunately the vacuum seal on the bag broke and they won't store now (I guess that's an argument to buy smaller packages). Given that it's unlikely to be stranded more than a few days, I'm not as concerned about food as some other more vital items.