I wouldn't use straight gas, old or new, to start a fire. Even mixed with motor oil or diesel it will still flame up if the gas is still volatile. l left some untreated gasoline in my zero turn once and the next spring it wouldn't start or even backfire. I poured out the old gas in the gravel in front of my shop, threw a match on it and it didn't light, after several matches hit in the pool and wouldn't lite, I had to try something else. I got my propane torch and heated the gas up for a few seconds and finally got it to start burning and it smoked like burning an old tire. I could sure see why the lawnmower engine wouldn't start with it in the tank. Luckily we new gas in the tank, it started right up so I lucked out with no carb repair needed.
I have since never stored engines with untreated gas in them. A double shot of Red Stabil keeps the gas usable next spring. I do try to only put a small amount in the tank, less than 1/4 tank then fill the tank in the spring with fresh gas. For small engines like a push mower, I drain the tank and store them dry.