Southpaw - well first off, this is all just ideas and plans right now, so I cannot speak from actual experience. With that caveat, it seems to me that that you can put one of those cheapo aquarium sticky thermomter strips on the side your fermentation vessel to measure its temp. You could then drop the thermistat temp to below your target fermentation temp (I'd would guess something like 8-10 degrees lower when fermentation is very active, less as the fermentation activity and resulting heat reduce). Thru trial/error I imagine you will be able to zero in on where you need to set the thermistat temp to get your fermentation vessel to a certain temp within a few degrees variation. The trade off I would think is that you gotta pay more attention to your fermentation (and open the fridge door alot more) and adjust on the fly as opposed to setting it and leaving it, along with more temp swings depending on how much attention you do pay to making adjustments. I'd guess it would work pretty well without the thermister extension, which is really more for convenience than any anticipation on my part that it would make that dramatic of a difference in the final product.