All other things being equal, a person with a larger larynx will produce lower notes, but there are many complicating factors.
The vocal cords produce the sound, and longer vocal cords will generally produced a lower note. Because they lie across the larynx, the length of the larynx does not directly affect the pitch produced by a voice.
The vocal cords, which actually generate the sound, are acted on by muscles. One set of muscles stretch and thin the vocal cords, producing higher notes. Other muscles thicken and shorten the vocal cords, producing lower notes.
It may seem paradoxical that while longer vocal cords produce lower notes, the lowest note of a particular singer is not attained when they have their greatest length. Compare this with a rubber band, which sounds a higher note when stretched out.
In general, while the dimensions of the larynx influence the range of notes which can be sung, they do not constitute an absolute limit.