I have bogs in Boston. VFT's will make it just fine as well as the vast majority of Sarracenia (I've only had 3 species not make it through the winter). There are also many Drosera you can grow in 6b....intermedia, filiformis, rotundifolia, x anglica, x beleziana, x hybrida, linearis, binata, binata var. dichotoma and x obovata.