So after some more fussing and whatnot I think I've got the fermentation slowed enough that it's no longer causing problems.  I swapped the insulation wrap over to cell no.9 so no.10 could cool off a bit, but it's still on the warm water circulator.

In this pic you can see the copper coil and hoses of the water circulator on no.10 and my makeshift "insulation wrap" on no.9... Everything I do is D.I.Y.

Here's the other half of the warm water circulator, 5gallon bucket, some fuel line hose, a pond pump and a fish tank heater.

Anyhow, so no.10 has somewhat stabilized in the low 200-210mv range.  We're around discharge day 5 of this new cell.  Meaning it's been discharging to a 270ohm resistor for about 5 days now.  I looked at my notes:

Sorry for the terrible penmanship..  Cell no.9 was at discharge day 5 on about 8/16 so we can see that we are still tracking fairly well, especially since we've not been exceeding 18.5degC with cell no.10 in these lower ambient air temps.