In Montana, our coldest months tend to get inversions that block much of the sun.

During those periods, I want the radiant heat from the black roofing felt.  It we go weeks without much sun and extreme cold, the bees may consume all of the food from the frames over which they are clustered.

Moving to one side or the other to access honey or going to those peripheral frames to move honey stored in them occurs during those periods of activity that you describe. 

Occasional increased activity is what I want to see, if it makes the difference btw moving to survive or dying from starvation next to frames filled with honey.
Now, if you bubble wrap keeps them warm enough to move when needed, then this is a mute point for you.  My losses from starvation occur in unwrapped colonies around Christmas or in mid-February, when we tend to get prolonged cold snaps and ground fog, some times for days or even a couple of weeks.
Jerry



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