I only have a few hives in wood boxes (most are polystyrene) so I’ll refrain my saying much here since people who actually use tar paper would be a better source of input. The bee books I’ve read typically recommend a tar paper wrap for northern locations to give the hives some solar gain on sunny winter days and as a wind break. The bees should have things propolized together pretty good at this point, but a wrap is double protection from the wind. The bees will be making a lot of moisture in a wood hive and hence a top vent also seems logical and is generally recommended by the books I read on wood hives. Like I said, I use poly hives.
Last time I knew, the commercial guys around me were not wrapping because it’s a lot of work to wrap 500 hives and they have figured out what works good enough for them to make a profit. One commercial guy says his “secret” is the put candy boards on top of the hives in Jan/Feb. While that may be a good idea, we should also respect the fact that the commercial guys know how to get their hives properly prepared for the winter (feeding, combining, etc) whereas us hobbyists’ tend to make mistakes. I think if you’re wintering in a wood hive, the tar paper idea is some insurance against our mistakes.