NZ has an extensive hut system, especially on the South Island. It gives you a chance to socialize in the evening, plus shelter from the everpresent storms, then in the morning, people depart at their own pace. I've done tracks alone or occasionally met up with another solo hiker and hiked with them for a few days. It is a great way to hike alone, yet spend the evening with others. Once in a while you will find yourself in a hut alone, especially in the mountains, but the huts on the lower tracks usually have at least a few people staying in them most days, especially during the summer or school holidays.