I have done centuries on a fixed gear, in the dead of winter, I had a rack with a pannier so I could take off or put on extra layers. I have thought of touring fixed, but in the long run, or just old age, or experience, it's a young man's folly. For me the toughest part of touring is the wind, I don't care if it is at my back, it will be in my face at some point, and loaded and riding uphill into the wind, I just couldn't see doing it on a fixed gear. I had to take a break on the LHT.