Again, I’m puzzled by the quest for a perfect CWOP score. If CWOP is all that great at calculating what the weather conditions should be where you are, forget the weather station and figure out how to get them to calculate your weather data for you. Carried to its illogical conclusion, CWOP would only need one weather station in the country, and then be able to calculate the conditions for everywhere else.
The truth is, weather conditions are just too variable for their numbers to be more than a general guide. Right now, here, there is almost a 10 degree difference across 300’ horizontally/100’ vertically from up here at the house to down in our woods.
And, based on your photo and description, the weather station itself is the least of your siting troubles.
You can extend the Davis wired anemometer more than 40’. I’ve done it. Mine is at least 140’. There is an app note on their site about how far it can be extended, and how the distance affects the top measurable wind speed. You can also extend the cable from the wired ISS to the console. I’ve forgotten exactly how far Davis says it will go, but I believe the spec for the protocol they use is 4000’. My farthest console (I have 2 in a daisy-chain) is at least 300 cable-feet from the ISS.
Learn to compromise, or drop a wad of cash to do it “right”.