Guess ill have to try it that way sometime then. So far I've doubted it working since our garage is attached, the eve isn't very outcropped and I would think (sounds like incorrectly so) that it would all just blow into the garage. I guess my biggest issue with leaving the garage open though is someone coming by and stealing from my garage, especially on an overnight smoke...
Living in the wet PNW, I smoke in the garage most of the time. I just wheel the smoker until the stack is under the eaves, and let it go. Never had a problem with smoke getting into the garage or house.
Anyway if its a mid-day sort of smoke I may try that next time it rains. Ive been doing it on my covered front porch, and that works fine too.