Hi Mark, we usually get good reliable snow cover but this year was rain. I usually pile extra snow on top only because there isn't anyplace to put it when shovelling the sidewalk. I too have found the winter wet is what kills them, NOT the cold (but that depends on what varieties you are growing as some won't survive extended dry cold periods either). Some of the opuntia are covered with pots to prevent snow getting on them as that is enough to rot them while most get no cover. I have some pictures I'll upload later as they don't want to upload this morning for some reason.
