My fiance and I were invited to his dad's cousin's son's wedding (does that make it his second cousin?) He has never met the groom, (nor knew he existed) and obviously we don't know the bride. It was nice for them to invite us. Their wedding would require us to travel, so we will not be attending (not to mention uncomfortable since we don't know them). I would like to send them a card as a thank you for inviting us. Should I be sending a gift as well? Is that too much for someone I've never met?