Scenario 1) Temperature is very low for a very long time draining the thermal batteries (honey frames) thus causing cold contact point below DP (dew point)
Here is an image of what triggers condensation. You see that my hive technically got their 1st dose of condensation along the mid side wall in my insulated/no top entrance configuration at the mid point of our long cold snap The red bars on the lower/upper charts show where the internal side areas internal temperature drop below the dew point. You will also notice that the mid top temperature is "comfortably" above the dew point (calculated from the average of the 2 RH% values and associated temperatures in the center of the hive. The cluster is actually located just above the lower entrance at the front of the hive and the T - sensor are about 1/3 from the back side of the hive. This is actually the best position for them to "re-heat" the whole hive volume using passive rising heat coming off of cluster. I am guessing the lower bee insulating mantle is much tighter at the bottom and the top mantle are can be "regulated" to let more or less heat (moisture) out based on their needs.

Scenario 2) Temperature quickly rises after being cold, thermal batteries are their lower limit, RH% increases in hive due to warming temperatures at core, however this humid air comes into contact with chilled contact point below DP (e.g. side walls or underside of hive cover)
In the near miss example we had a 17C(30F) (delta warm up) in 7 hrs. I chose this point as this is where the sidewall temperature (Ti) hit its lowest point and started to climb (thermal lag due to honey frame thermal "battery") just missing to cross over with the dew point.

Smaller clusters in too large of a volume would run the risk of wetting themselves 

I will be taking some observations for the rest of the winter (hopefully find an IR camera) to better understand this process.

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