Several companies make a "travel guitar". I have taken my Martin Backpacker to Jamaica several times. It's in a gig bag and usually can go overhead on the plane. It is probably not loud enough for your needs unless it is plugged in. Taylor makes a nice sounding travel guitar called a Baby Taylor.
Another thought is most music stores carry "starter" guitars from $60 to $120. Though they won't get the sound of your favouite ax, they are playable and would get you through the ceremony. If it gets damaged, it's not a life changing loss. Like Accompong says above, it would make a great gift to leave.
Respect