I love Sibleys, but ....
Yeah, there is always that "but".
Parking is almost non-existent. There is not enough room (usually) to get a group of 8, let alone the numbers good BBQ might bring out. It's too far South for the folks who hate driving outside Chippenham Parkway/288. (OK, it's not really that far outside 288.)
That's the problem of being popular - we can get too many folks for the good/great places to be able to accommodate us.
That being said, I think it would be worth the effort to try having a dinner there just to see if we could pull it off.
stay safe.