Hard to say about the street light, how far can you get from it ? Artificial lights loose their power dramatically with distance. I had a roof top grow last two years, and a street light approximately 100 feet away did not affect flowering.
Could you maybe make a barrier / wall ? It would be nice to see what that monster would look like this fall.
...quick research...Cannabis can handle up to 1 LUX (brightness of a full moon ?) without being affected.
You could , make a cheap hoop house, and tarp it at night, pain in the A. but benefit would be you are ready to cover in case of heavy rains, keeping your buds drier.