Winter camping, with its reduced hours of daylight and cold temperatures puts greater demands on a headlamp.
Here are my suggestions for good winter headlamps.
1. LITHIUM BATTERIES> MUCH better performance in the cold than any other type. Plus, they are very lightweight and carrying spares is no burden.
2. REGULATED CIRCUITRY> Gives almost constant brightness level until the last few minutes of battery life. I prefer Princeton Tec regulated headlamps for utter reliability but Mammut now has a great headlamp too.
3. HEADBAND REAR MOUNTED BATTERY PACK> Necessary only if you plan extensive use of your headlamp, as in 4 AM "alpine start" hikes to conquor a peak. The rear mounted battery pack keeps batteries under your hat/ parka hood and warm, giving more battery life and room for more batteries for a brighter light bulb.
4. WATERPROOF "O-RING" SEALING> This is a must for almost any headlamp and most have this feature.