I will suggest from motorcycling experience that you will need a light at LEAST as powerful as a scooter headlight to snowboard with at night if the slope isn't lit up. Any lamp that fits on your head powered by a tiny battery won't cut it (unless they are hella bright, hella expensive LEDs).
Looks like a decent idea so long as you can still see where you are going.
For night riding this year I am trying one of those head lamps that has the bright LED lights on them. Here is the one I will be using; says it shoots out to 80 meters...
BLACK DIAMOND Icon Headlamp - Eastern Mountain Sports