Very few of the reliable fire making modes weigh significantly. Well made wooden matches have always worked for me - a waterproof capsule full of them along with a striker and a modest amount of tinder weighs maybe an ounce and will get you flame when you need it. A fire won't make your night out luxurious, but you will survive.

Lately I have taken to scattering mini-Bics through all of my packs. They are cheap insurance and pretty reliable.