After sort of walking myself through it, as her, I can't understand going there after the date. It was late, cold and why go? So I keep thinking maybe someone knocked on the door, someone she knew, she gave them a ride and then something went very wrong. I think they drove her car there to confuse LE, to make it look like she went there and left with someone. JMO. No proof, just going there to take a boat ride or giving someone a ride there, makes no sense to me. There are so many places better to meet up.
She may have been stalking him. I'm saying that because I had a friend in a similar situation. She would get up in the middle of the night just to drive by his house. One time she sat outside his house and called him. He didn't answer so she left a message telling him he better call her back or she will be knocking at his door. He called right back.