We have decided to bring Tristan to the ceremony. On our last 5 hour drive he was completely silent and happy. As long as he has his blanket, he's fine. I think they would want to meet him and I think he would be a comfort... definitely for me. It will also be nice to get some pictures of him at the memorial since she is his namesake. Thanks for all the input, everyone! You all really helped us make this decision.