We claim the ornamental design for the free standing champagne cork holder, as shown and described.
FIG. 1 is a perspective view of a free standing champagne cork holder embodying the invention;
FIG. 2 is a front view of the free standing champagne cork holder of FIG. 1;
FIG. 3 is a top view of the free standing champagne cork holder of FIG. 1; and,
FIG. 4 is a right side view of the free standing champagne cork holder of FIG. 1.
The broken line showing the environment is for illustrative purposes only and forms no part of the claimed design. The bottom view, the left side view, and the rear view, form no part of the claimed design.