DayZ
Sakhal servers
Online count loads with the directory.
Sakhal is the winter official map. Cold is a mechanic, not a backdrop: you plan around heat, fishing, and boats as much as around gunfire. The directory records it as sakhal. It is newer than Chernarus and Livonia, and the servers that run it usually say so in the name.
You need the Sakhal DLC to join. Populations are smaller than Chernarus. The servers that are full are usually full for a reason: a fresh wipe, a known group, or a ruleset people already trust. Open a dossier for the official flag, the mod list, and whether a password is set.