Would wrapping now be a good idea?
I wouldn't do it at all. My first year I wrapped with roofing tar paper. I bet it kept the hive warmer but even with open SBBs, it was really wet inside. I haven't wrapped since and I've noticed that it is much drier inside the hive, except for the inner cover where water condenses. I crack the inner cover with shims to help the moisture move out. Save your money and forget the wrap. They'll be fine without it. Ventilation is much more important.