By Vassia Barba An experienced hiker who had accomplished the “Triple Crown” of challenging cross-country trails died in New Hampshire’s White Mountains during a solo hike in brutal conditions, including single-digit temperatures, harsh winds, and waist-deep snow. Christopher Roma, 37, was an expert hiker who ran his own long-distance trail guide business and had walked this familiar trail many times before. His mother, Barbara Roma, said: “Once you get to a certain point, you have to make that choice to continue or turn back. And he was never really a turning-back kind of kid.” Concerned frie…