I too have been thinking about this solution to the overcooling problem which is worse on the Stelvio NTX due to the huge oil radiator. When I ride in the rain the engine cools so much that the ECU shoots more fuel into the engine and my mileage goes to 30 mpg or so. On a cool day the engine seems to take forever to warm up and probably never does get up to full operating temp. It will be interesting to see how you add this to your Norge.
Peter Y.