get a card the present will be shipped to their casa
They provide a shipping address for the registry, so order it and it will be shipped wherever they chose. Since it’s a destination wedding, you’ll be doing them a favor by showing up with just a card. They’ll know you sent a gift as well.
Get a card. No food or flowers or alcohol, they should have enough of all these at the wedding. They better 
As for accommodation - http://finance.yahoo.com/news/man-rents-out-back-of-van-on-airbnb-for--99-night-192424785.html
^ Does he provide free candy?