NiCD or LiFeS2 for low temp?

I'm debating on whether or not to use NiCD cells (provided with the
radio that is using the cells) or substituting these cells with
Lithium-Iron Disulfide cells (AA provided by Energizer) for a high
altitude application where the enclosure temperature could easily drop
below freezing.  From the spec sheet on Li/FeS2 cells, they can
operate down to -40C.  However I have not found concrete information
on the low temperature limitations of NiCD cells.  Does anyone have
experience or information that they can provide?

In addition, I was wondering if both cells would be able to provide
the needed 700mA while at low temperature (say, -20C)?  The discharge
profile will be approximately 16 second at 700mA, with 180 seconds at
70 mA in between the 700mA pulses.  This profile will last for about 3
hours.

Any information that can be provided would be greatly appreciated!

Thanks in advance!
Dave