In reply to PeterBlackler:
Not so sure about the campsites but I think the Ilot Bosquet one is more basic. It's a nice spot with some bolted climbing on boulders in the woods.
It should be fine parking in the Moiry dam carpark overnight.
The hut is only 1.5 hours walk, so carrying some extra food isn't really a problem. If you're there for a couple of nights then taking some extra snack food and lunches would save some cash. Food at the hut is good - it's hard to resist the chocolate brownies...