OK Huck, here's what you are looking for about the greens. Fescues do not like to be cut below 2/10 inches, approximately. A fescue green that is dry and cut at 1/4 inch will still roll about 9 feet. I played Pac Dunes on opening day with the fescue greens at 3/16 inch, too short for long term fescue health but only cut for the superintendents playing that day and rolling 10 feet plus. My understanding is Pac Dunes maintains the fescue greens between 2/10 inch and 1/4 inch for normal play.
The fescue greens at the Brit Open might be cut at 3/16 inch for speed and require a little more water to keep them helathy from diseases.
The fescue on the rest of the course will come back with judicious amount of irrigation over a period of time. There will probably be extensive repairs to areas trampled by the fans. The reason the turf is only dormant is the amount of aeration done to the turf prior to the Open in the spring. The more aeration the better, there is never too much aeration. Aeration allows the roots to dig in deep and survive the hot summer heat. Since greens are the most aerated of any area of the course, that turf will be greener than the rest if kept at the correct height of cut and syringed with water.
I wish I could do all that at the golf course I manage.
Troy