Its tough in those conditions, ive WD from it after just pure frustration, ive also posted 59, 60,61, ive won it on 63 once i think. -7 on a Full 18 Ready Go should not win, you need to be tenacious playing it.
Worst part was when i shot a great 65 and Bollox came in with a 58, i thought, WTF.... on my 59 i was hitting my irons great, had some holes that i couldnt reach and some that played short.
But, even if you dont shoot as low as you want to, you still get in the money as ppl WD from pure frustration.