Peri is possible with a large B to C but it's a bit hit and miss and will probably require revisions. I know that Garramone for example won't do peri on anything other than a small A, whereas Lena Andersson has been known to do the procedure on Cs.
The general idea is that if the skin folds under the breast, peri isn't the best option. Any sagging or loss of tightness (often caused by long term binding) is pretty much a no-no too.