I left my 3DS at a relative's house yesterday! Not only do I not get to participate in the Festivale (due to me never wanting to time travel), I have the fear that I'll lose a villager! If one was thinking about moving, then they'll probably move.
You should call your relative. Does this relative live even slightly nearby? Maybe this relative could drop it off or you could pick it up. If this relative doesn't live nearby, ask your parents what you should do.