You mentioned operating in cold conditions. You might consider having a set of disposable lithium AAs (if your camera can accept them) as a sort of second backup. Lithium batteries are quite good in cold weather, although I think Eneloops will work fine for the limited times you mention.

I am phasing out conventional alkaline AAs and AAAs, and using primarily rechargables and lithiums. Vastly cheaper to operate equipment that way.