Congrats on snagging a dinner adr for Le'Cellier; Just go there with a realistic expectation of this place and you'll leave happy. So many, including myself, have gone there expecting a earth shaking, almost out of body experience only to find it's a decent place much like an Outback, but far from great. For me, it's hype is more sizzle than anything.
Is it a bad place? no. Is it the greatest place in all of WDW and much of the universe as some euphorically proclaim it to be, no. It's typical of just about any other WDW restaurant, good, but not great. JMHO.
Not sure of the closing time but they won't chase you out of the place. Take your time and enjoy!