I would worry about your kids opening and closing the front door and the dog running out and getting lost. That's honestly my biggest fear when we bring our dogs anywhere.
This. Are they bringing a crate. That may be helpful during some times.
BTW Op, I'm a dog owner and I do occasionally ask if I can bring our dog - but I would never expect a "yes". I would like to know how the host really feels and not have the host say yes out of any feeling of obligation or being nice. AND I would need to know yes or no in a timely manner. Kennel reservations can be hard to get over the holidays and pet owners are often particular.