Just three games into the 2003–04 season, Schremp was traded to the London Knights, the team with which he would spend the final three seasons of his OHL career. He began to impress during the 2004–05 season, scoring 41 goals and 90 points in 61 games as well as 13 goals and 29 points in 18 playoff games as he helped London win their first Memorial Cup. That season, Schremp was also selected to play for the United States at the 2005 World Junior Championships, where he scored four goals and five points in seven games as the Americans finished in fourth place.