at the end of part 1 the story explains that “dexter was unconsciously ruled by his winter dreams.” what does this mean?

Dexter does not know what to do with the information that Devlin has presented him concerning Judy. He feels as if his dreams no longer exist because Judy is no longer what she once was. It was not that Judy could not commit to a man, it was just that Dexter was not the man that she wished to marry. His dreams are dead, and without his dreams, Dexter has nothing.