I believe the composite Championship course at Adrian's Player's Club includes one hole that is a combination of two 'normal course' holes and has an overall length of something like 720 yds. Par-6? I think the composite course plays around 7,800 yds and believe they hold an annual very back tee challenge event for amateurs as well as a Euro-pro event on it. I'm sure Adrian can chip in with more specific details.
I remember as a small, short hitting kid in the Far East playing a 600+ yd 'par-5', I'm talking early 1970's, seemed like a par-10! Driver, fairway wood several consecutive times, iron to the green and a couple of putts. Easy to forget that there are a lot of effective par-6's and 7's and 8's etc when you're a young junior, or, and getting there these days, a senior. Same for ladies I'm sure, but that's one of the reasons we have handicaps.
On a slight tangent, the altitude of a course and also the relative humidity of the air must play some relevance into a holes effective par.
Atb