Inert objects aren't affected by temperature and wind chills and such. If they ever get filled with water and freeze...that's another problem...
I wash my bottles in bleach water...if you do not rinse the bleach off and let the bottles dry you can "cap" them with aluminum foil or plastic wrap which will keep the dirt and bugs out. I read they will stay disinfected for a year.
I do all my bottles this way. It is also an indicator as to which bottles are "disinfected" or just "rinsed" or "washed".
Remember, you still have to wash the bleach off with hot water prior to use.