last time we were down we watched the show from the pier along side of Lombard. One of the best places to watch the show!
How fast do you eat. if you sit down at 5:15, order by 5:30, food comes out by 5:45, and you are done at 6:30 you may have to "milk" the time a bit before 7pm.
Order an appetizer, eat slow, order a desert, and then once 6:50 rolls around go outside, watch the show come back in and pay.
I did this at Disney Contemporary resort once. We got an early reservation at say 5:30 and the fire works were at 9 something. I ordered an app, a bottle of wine, which we drank very slowly, slowly ate our meal, then I ordered a cheese plate with crackers for desert, sipped on coffee. Doing this enabled us to sit there until the fireworks were ready to go off - walked outside enjoyed the show, came back in, gulped down the rest of my coffee - paid my bill then left
It was a pricy bill - but a good memory