Make a cone shield out of 2 foot wide aluminum roofing flashing. drape the flashing around the keg or kettle, shape it like a cone tight at the top, but not too tight cut tabs all along the top to hold 1 inch off the kettle prop the v of the cone over the tap. It will block the wind and double your heating speed (Yes it will- because the heat will run up the side of the keg and out the top instead of blowing away) PS: you will find it also works wonders keeping the heat in even in the garage. I will see If I have pictures.
A roll of flashing is about 15.00 bucks and it will do 2 kegs.