Wendy:
The moon will be much brighter than any of the landscape it lights up, so you'll have to settle for a blown out moon unless you try shooting with a gradient filter (at least 3x, probably more). Alternately you could do an "hdr" shot sequence: one exposed for the landscape, another exposed for the moon, and then combine the two in p-p. Patching the moon into other photographs can be tricky. There are some on this forum that can spot that kind of trickery
BTW, since when is shooting in -20 deg C weather tough?
Roger