Have fun, wish I was there. Sounds like a blast! Also glad I gave you a chuckle.
I say start an hour ahead of time. Make sure charcoal is well burned then cook the chicken, as it gets ready set it aside and then throw back on the grill just to warm it up. Or even better keep aluminum trays on the side of the grill. They, the chickens, will be hot enough to serve.
I hope vagriller didn't get washed or blown away by the storms last night. They were moderately fierce around here. Not sure where he was gonna go campin'
...1/2 chickens are fairly forgiving...