When planning where to have the ceremony in an outdoor location, check out the area at your wedding time. Look where the sun will be.. and locate yourselves so that neither your guests or yourselves will be blinded by the sun. This is of particular importance later in the day, when the sun gets closer to the horizon. I have officiated at a wonderful evening wedding, that took place at dark. The couple had a chandelier hanging from a beautiful pine tree. While the lighting was great for us, the photographer had difficulty getting pictures of the wedding party coming and going as well as pictures after the ceremony as it was dark. Consider what pictures are important to you.
Plan well and then enjoy your day. If it needs to be moved indoors, remember its the wedding itself that is important… not so much the location.