Dressing down a black dress?

I am attending a wedding about an hour away and camping the night out there. I just bought a little black dress to wear to the dinner, but i'm not too sure where i would be able to change into my black dress after the ceremony. I am planning on just wearing heels and some jewlery and carry a black clutch with the dress but I was thinking maybe i can wear the black dress to the ceremony..but dress it down somehow? I'm not sure how to do that though...what can i do? The black dress can be worn strapless or with thin straps u can add on..hmmmm any help would be great!!!!