Wilson was on the downhill slide by 1916. I doubt very much that he could come close to his 1912 showing.
Nevertheless, Wilson wins by a larger margin in 1916 with Roosevelt as a candidate than without Roosevelt as a candidate.
Hughes was a much stronger Republican candidate in 1916 than Taft was in 1912, and Roosevelt would not have the same impact in 1916 that he had in 1912.
Roosevelt was 4 years further removed from public life in 1916.
Wilson 289 (instead of 276)
Hughes 220 (instead of 255)
Roosevelt 22