If you're going to plan to potentially got 12 days or more between resupply I'd suggest packing a few NRG-5 style ration bars for emergencies. I usually take a package or 2 with me just in case. 2400ish calories, 72g of protein, and are vitamin fortified. At about half a pound each.
The stuff isn't actually all the bad to be honest. Similar in flavor to shredded wheat with a little bit of sweetness. Mix with water and some dried/dehydrated fruit and makes a decent breakfast porridge.