I thought about the original post, and want to give the OP something to think about.
Scenario...the five of you are seated and waiting for the first course. "Evil" starts up, and you leave to go outside. In the meantime the appetizers are served. The waiter waits for you to come back, and then brings dinner. "Evil" starts up again. You take him outside. Dinner gets cold. Dad is having conversation with his two older kids, but not "the family". You rejoin and pick at cold dinner while those seated around you start to wonder when "Evil" will be at it again. Because you've been outside for most of the meal, the service has been very slow while the server waited for you to get caught up. Now the older two are antsy and you are eating cold food.
Who's having an enjoyable meal here? By your very admission, you expect to spend much of the meal outside with "Evil". That doesn't sound like a "Family meal" to me.
That said, why not look at places that are more appropriate for a family with kids, a place where there will be other families, a place that can be a little noisy, and where "Evil" won't even have an eyelash batted at him/her until a total and complete meltdown occurs, a place that is fun.
I'd suggest Mama Meroses, 50's Prime Time, Teppanyaki, O'Hana, or the Whispering Canyon as better alternatives for a much more relaxing, and enjoyable meal.
One other option would be to hire a babysitter to come to the room on another night of your trip and have a quiet night out with just the two of you to dine at a quiet, adult restaurant.
Also, if you were ready to splurge for private dining at the GF, how about on the Grand One. Totally climate controlled, and even if the weather is bad, you'll be inside. The kids LOVE being on the boat, it's easy to corral a toddler (been there, done that!) and because it's jsut your family, no worries about disrupting anyone.
I am certainly not trying to flame, just food for thought.
Anne