The piccolo in C has a range from D5 – C8.
This means that the piccolo’s range is an octave above that of the flute. The addition of a footjoint to extend the compass downward is not usual on the piccolo.
Theoretically, adding a C foot to the piccolo in C can extend the range down to C5 (by adding a B foot it can theoretically be extended even as far down as B4). Giuseppe Verdi in his Requiem and Gustav Mahler in his 1st Symphony ask for C5 as the lowest piccolo note.