Bring lots of memory cards too. I also used a 70-300 for some good DOF shots and for when I wanted candid ones where I don't want people posing all goofy. Remember that people eating make bad photos, unless you want the bride and groom taking a bite of the cake. Hopefully if inside they have a white ceiling so you can bounce the flash off it. Straight on will cause much unwanted shadows.

"The happiness of a man in this life does not consist in the absence but in the mastery of his passions."