Wolf- The loshon we say is ?????? ????? ???? ????????????? ?????? ????????? , any GOOD minhag that we have done. If you consider buying Coke a good minhag then go be matir neder!!
passfan- The minhag was started because of strigency,not convenience. “I live in an area where its so easily available, so why not?” Since it wasnt inconvenient to eat c”y, she was stringent and started a god minhag of keeping c”y. Now that its inconvenient she needs to be matir neder.
Sam2- When one is matir neder, generally one needs a pesach- an excuse as to why they wouldnt have made the neder. We dont say that the neder doesnt apply because this is what he had in mind when the neder was made. (Dvarim Shebilev)