The EWP goes by the Poly at 9:00, unless Wishes is at 9:00 then the EWP is immediately following Wishes.
Id guess the average meal at Ohana is about 1 hour.
If I wanted to be eating duirng EWP Id book for about 8:00. If I wanted to be at the beach to see it, Id book for about 7:00 just so I wouldnt be rushed.
Enjoy!