I keep mine in an unheated out-building with conditions similar to a garage. The modern day plastic powder containers seal and protect the powder very well. No issues and I am using some powders that I have kept for 15 or more years under these conditions.
Well....... pray tell, where do you live? Miami or Houston with 99% humidity? Or, Tucson, Az, or Columbus, N. Mex.? Give us a break: How do we answer your question intelligently without knowing the humidity factor???
I live in a waterfront home on the Delmarva Peninsula. 90-100% humidity is common place. I keep all my powder out in the garage. To my knowledge I have never had a powder related failure in my handloads.
IT seems to me you would be more likely to get condensation in your powder if you keep your powder in the cold gauge then you bring it inside to load in a warm room. ITs like this if you wear your glasses outside in the cold and you come inside where its warm your glasses fog up....... I call that condensation! so your powder will do the same thing when its cold.
Myself I keep my powder right under the reloading bench in the basement.