There's always time for off-camera lighting; that's why you have it with you! Even a simple hand-held speedlight would have made a huge difference to the exposure here. As I said, the left side of her face, arm and dress are blown, and her right eye is in deep shadow. There's very little detail visible in the dress. A wedding dress is one of the highlights of the event; women can pay $5, 10 or 20K+ for them, and a bit part of your job is nail that dress.
I understand completely that you may have to "suffer" with the location, but WHY would you shoot this at f8? do the stairs and handrail and yellow whatever-it-is inside the house have special meaning to the bride? This should have been a 200mm at f4 shot, NOT an 85mm at f8 shot.
The problem with wedding photography is that there are no 'do-overs'. If you mess it up, it stays messed up. That's why good wedding photographers charge what they do; they have the skill to get it right the first time, [almost] every time. IMO, based on these points, this image is one that should have been left on the cutting room floor!