My week at Ganton was in 2012 during a bone-dry September following a drier than usual August. I thought the fairways per se were wide enough for play in the 10mph breezes I had most of the week. Only one round was some serious wind, gusting about twice that much, and I found the "rough" quite often. But it was so baked out that unless some wispy stuff grabbed the hosel, no worries. Flyers galore but no wedge out sideways type stuff.
I'll take Mark and Sean at their word that serious vegetation like gorse and shrubbery do impeded play but I have to wonder whether some of that encroachment has been since 2012. I only recall a couple of holes where I felt like I needed to steer well clear of that sort of stuff by aiming away from the obvious playing line.
To my memory, much of the heavy upright vegetation was far enough from the fairway that a rolling ball would be stopped by the rough and an aerial shot would have to be seriously errant (again, with the exception of 2-3 holes). In any case I'd say more than half the holes were fairway/rough/bunkers only in play and my impression was of sufficient but not extreme width.
Usual caveats apply. Memory is from 3 years ago, I am a very short and usually somewhat straight hitter and I doubt I encountered any winds or gusts over 20mph for more than 45 minutes total during my six rounds.