I love night riding and winter gives me a lot more opportunities to do it. With snow I find I rarely need to run my lights on anything but low (though low is 800 lumens). Definitely need a helmet light for riding trails in unlit areas.
I started a ride at 1/4 to 8 in the morning yesterday and it was still dark. I rode in the dark most of last week because the days were warm and I was trying to ride while the roads were frozen.