I don't have any experience on kolsch, so I am not going to comment on any of the recipes. However, I did just brew a Altbier that was on the light side (more Munich next time). Its currently lagering outside on my back patio, covered in a towel, and sitting in big bucket full of water. As far as I have noticed, the beer is down around 45 degrees or so, and I don't have too many temperature swings with the large amount of liquid (close to 15 gals) creating a lot of thermal mass. YMMV, especially if you live in warm areas.