Probably not much comfort, but almost the same thing happened to me in the early 80's I had just got my new smoker/grill combo home, cooked a couple of small quick things and ready to try a brisket. Got a nice Big brisket seasoned it up, built a fire in my smoker and put it on. This was late about 10 or 11 PM I was going to smoke it all night, check it in the morning and wanting it to be ready by lunch. (have to remember I was a rookie just starting out, no cell phone, google or SMF) Stoked up the fire box with wood and went to bed. Got up early all excited,went out to check my brisket expecting to see and smell something wonderful, I knew something was wrong when I didn't see any heat rising off the smoker, opened the door and it looked just like it did when I put it on, Fire had gone out and it had been sitting there all night. Straight in the trash as bad as I hated to, and back to the store for another. The reason my fire went out was all my fault. As I said this was a new smoker I designed and had one of my welders fab. It was a combo unit smoker and grill straight flow design. it had a damper between the FB and CC which I failed to open.
Gary S