James:

I'd like to suggest one solution for grid-down insulin refrigeration: I have purchased a Dometic RC4000 3 way portable refrigerator for insulin.  It runs by 12 VDC,  120 VAC  and LP gas.  It is an absorption type ammonia system (as used in recreation vehicles) and appears to be a high build quality unit manufactured in Hungary.  It is the size and shape of a large wheeled ice type cooler but with only a small 1 cu ft cooled area.  It is perfectly suitable for long term insulin protection and uses 1 lb of propane a day  =  18 days from a typical barbeque-sized 20 lb tank.  With no moving parts it is expected to last a long time. [JWR Adds: These can also be plumbed to much larger domestic propane tanks. Or, if you have a large tank with a "wet leg", you can refill small tanks from it, repeatedly, if you buy the correct adapter fittings. Call you local propane distributor, for details. Be sure to consult your local fuel storage ordinances before doing do.]
 
Performance is as follows:
13.3 VDC @ 6.0 Amps  is  unregulated at 40F below ambient.
120 VAC has a 7 position thermostat and regulates from 22.5F at pos 7 to 42.5F at pos 1.
LP gas with regulator (supplied) has 3 settings providing 20, 30 or 40F below ambient.  The regulator required adjustment but was adjustable.