I sent an eMail to Cottage Water Supply Inc, the makers of the water system we have installed, on Monday and immediately received a response. And a very positive, hopeful one at that.
It appears that the section in the pipe that is frozen is likely a dip in the water line down to the lake. It is at this dip that the water would pool rather than drain fulling back to the lake, hence freeze.
How did Adam Soszka at Cottage Water Supply determine that that is the likely culprit? It turns out the gurgling sound that we hear when the water is being pumped up from the lake is most likely caused by the air flowing through the water in the 'dip' as the water first starts pumping up to the pressure tank. A find this so amazing, but also indicative of someone who knows his products. It reminds me of my son (he is a mechanic) diagnosing an auto engine problem by listening to it through a stethoscope - yes really.
I still will have to wait until the Spring thaw, but I am reassured that it is not a BIG fix.
;-)