Fatwood and petroleum jelly filled cottonballs for starters. Dead wood that is still on the trees, especially the small branches at the bottom of spruce, pine, or fir, burn well. And when all else fails, there is the option of bringing a road flare. I was on a backpacking trip in the Adirondacks and had conditions similar to yours - steady heavy rain all day, low temperatures. One of the guys pulled out a flare and lit it up. It did a wonderful job of getting a big fire started.