When I use the snake method, I make it three wide X two high, and add a chunk of hickory and a couple chunks of cherry wood mixed in with the briquettes. I run the bottom 3-way vent about half open, top vent always wide open unless temps get too hot and then I close it halfway and watch for temps to drop, usually within ten minutes. I shoot for cooker temps of 250°~275°, and I don't have a problem keeping my 22" kettle within that range.
Also, I use a drip pan but I never use water in it. The heat sink effect of keeping that water hot may have held your temps too low. Combine that with cold ambient temp & wind, and you might not have had enough heat in the cooker to keep temps high enough to cook.
Looks like a good save on the ribs, and a great meal. Don't give up on the snake method just yet, as you are on the right track.