I think most grilled meats can be held under foil in a warmer. I'd moderately undercook some of it, hold, then finish using the broiler.

The sides might be a tougher thing to hold for several hours, depending on what they are. Maybe hold some batches of potato salad in the fridge, etc.

I agree with John, but would specify meats that are meant to be well cooked, like ribs, shortribs, brisket or chuck. I wouldn't try with steak or tritip. Do label the pans with the time they came off the fire, and either reheat or refrigerate after two hours. If you put them to reheat in a low oven with a little moisture in a pan with a grid above to hold the meat, it'll retain its moisture. Only reheat once and make sure that the meat is cooled and in the fridge before 4 hours are up if you reheat in the middle.

You can use a fridge or ice chest to hold containers of sides that require refrigeration and only put small amounts at a time in the serving bowls. Just remember to dump out what's in the bowl into a "back in the fridge" container first, and then put the new in, or have separate bowls to switch out, so there isn't a small bit in the bottom of the bowl that keeps sitting out too long.

Be as organized as you can and you can pull it off. If you have a responsible kid or weird nephew with good focus, put that person in charge of the times so the stress is off you. If there are lulls, just put the perishable food away. Welcome new arrivals with, "Perfect timing! I was just about to heat up some 'cue and put out a new round of sides. Come, eat and enjoy!" If you're positive about it, they won't mind waiting half an hour or whatever it takes to get the food reheated and served up.

Have fun!

I'd do what Andie suggests and hold it in crockpots. It will be good for hours and hours.

I agree pulled pork will hold easily. Do you have a preference as to meat you'd like to grill and hold? We like tri tip that you can easily grill and hold as John mentioned.

Thanks for the tips and ideas! Either beef or pork would be my preference. I like the pulled pork suggestion. I wonder what I did with the crockpot. ;-)

The pulled pork sounds like it would make things easy and make the sides sound like the hard part. However, there are several sous vide fans here. If you happened to have the device or have thought about getting one, this might be the time to use dcarch's (and others') approach of placing some inexpensive beef (chuck steak or more likely roast for more thickness) into bags at something like 130°F for 18-24 hours just waiting to be pulled or cut off pieces as needed. Two to four minutes on the grill and zip you're done or longer for medium/well done.

I'd do pulled pork