I agree with Bob - High/steady winds present two problems (1) messing with air flow into the smoker and (2) cooling of the smoker's side walls [aka heat loss]. An ATC will help a bit with the air flow issue, but not the heat loss issue. The heat loss issue is going to be significant in Wisconsin, at least 8 months out of the year so I'd probably go with both solutions.
The fan on the ATC can allow a little air flow thru it even when it isn't running, so when the wind is blowing, the air flow side of the equation less stable compared to when conditions are less windy. Also, the fans for ATC may not really be designed to move "turbulent" air. There is probably some complex mass flow equation for blowers pulling from turbulent vs non-turbulent conditions but I'm speculating on that.
The Thermoworks SmokeX and Billows is a good set up. I noticed that T-Works has a cover now for their fan inlet to that allows users to cover the fan inlet partially and reduce air flow when the fan runs. My billows tends to cycle on and off quite a bit so I might try blocking off the fan a bit to see if the fan will run longer when it comes on. Maybe I could improve my temp control from +/- 5 to +/- 2
