The chances aren't great, as just about everyone has the same request. It is lots of fun if you can get a patio table. We have been there with the same request 3 times, and they were only able to seat us on the patio once.
We are trying again in October, as we are bringing our adult son to celebrate his birthday. I am hoping, but not planning for an outdoor table.
In my opinion, the food here is not the best available in World Showcase. It is not bad, just not the best. I think the menu is somewhat limited, and they seem to change it (not for the better) frequently.
I think you will enjoy yourselves, however. It is a fun place to eat, and as other posters have said, they do direct those dining inside to a spot to view Illuminations.
Have a Great Evening.