I visited southern Vermont over Labor Day weekend. The damage caused by Irene was extensive to roads and infrastructure, and not a few private businesses and dwellings as well. Pretty much everything that was in a river valley had some degree of damage. But it was all due to water - hardly any wind was seen.
As far as The Ledges are concerned, this is how it stands. First, the State of Vermont has closed all bodies of water affected by the flooding until further notice. That means that, even if you should find a way into The Ledges, you will find signs and maybe even people telling you to go away. Second, Rt. 9 from Brattleboro and from Bennington is closed indefinitely. Miles-long stretches of this highway was washed away by the Irene-induced torrents. Rt. 112 from Colrain is open, but only one lane exists at the moment, and there's a part of it that is missing just south of Jacksonville. I also wouldn't be surprised if the road into the recreation area was also completely washed out - and I have no doubt that repairing it will be low priority.
In summary, I'd only attempt this in September if I had other business in the area. I think it's going to be next season before things are back to any kind of semblance of "normal".