I have not done winter camping for several decades. And when I did that, it was with a small group, have not done that alone. I do recall one night when it was unusually warm (20s F) that we played cards for a while after dark in the tent, there were three of us. We were either using snow shoes or skis, not biking.

For it to be dark at 4pm, you must be at a Latitude of 47 or higher and have only 8 hours of daylight, 16 hours of dark. You need a good headlamp, good batteries, and having a second headlamp could be a good idea if the primary crapped out.

So, you should start setting up camp at about sunset. You might not start eating until well after 6pm because you spent so much time melting snow. You say you have the gear for it, what are you using for a stove?