FWIW, I have attempted to play a 7800 yd. course. I was at Kinderlou Forest in Valdosta, GA last fall, and on the second round of 36 hole day, decided I would go to the tips just to see what it was like. I lasted less than nine holes before I moved up; it was completely unplayable for me.
For reference, my index at that time was approx. 4.5, and while I'm no monster off the tee, length is not usually a problem. I often couldn't reach the fairways, even with driver; irons would have been completely out of the question. When I could reach the fairway, I couldn't get to the corner of the doglegs anyway.
And this was w/o Open rough and greens running 12 or 13, plus the added pressure of media, etc. AND, we were on the back end of an historic drought here, so that the course was running really fast.
In sum, I vote nobody (including Romo) breaks 85, and it wouldn't surprise me if nobody broke 90 either day.