Little French rolls, bagels, hard pretzels, whole-wheat tortillas and pita pack well. The only crackers I've found that hold up OK are Triscuits and Wassa Bread. 2,000-foot base camp at the base of Mount Whitney, camping in the snow, when our water bottles froze inside the tent and our frozen fingers couldn't manipulate the stove. I also discovered after my stove pooped out once that Ramen can be soaked, instead of cooked, to the proper consistency. Couscous and Minute Rice require only boiling water to prepare.
Carrots hold up pretty well unrefrigerated for a long weekend.
Jicama, while heavy, is highly nutritious and keeps better out of the fridge after it's cut. Some people can't stand the taste of water treated with iodine so need to mask it. When I was a kid, we always took Wyler's powdered drink mix, but now there's the incredibly concentrated, zero-weight Crystalite. . Dense cookies, like ginger snaps and fig bars, hold up well jammed into a pack. Baker's chocolate has a much lower melting point than a candy bar.