I have gone over my target finished wort a few times before and the beer still turned out tasty! Recently I tried to help my sis with a yard sale and brew an extract Irish Red in the same morning. With all the rushing around, I didn't add enough fermentables and used too much water. The beer turned out being very light in taste, and of course lower in ABV (3.1%). It was still great! My mess-up was bigger than just ending up with .5 gal more volume. Your beer will still turn out great!
"A bar is better than a newspaper for public discussion."
Secondary:IPA, just "IPA"
Bottled: Applewood Smoked Porter, Windy Bridge Stout, Maple Chocolate Pumpkin Ale, Maple Pumpkin Ale, California Steam, Black Cat Porter, Irish Coffee Stout
Kegged: Blackberry Stout, Nut Brown, Sweet Cider, Apfelwein #2, IPA, SNCA Clone