I have a closet in my living room (coat room?) and no matter the temperature outside, it is always slightly cool, and there are no windows. I usually keep my clear bottles in there and anything in an amber bottle (or blue) I keep out near my couch for easy access. I've read that light can weaken the Vitamin N (nicotine) in juices, but I have not had experience with those effects. I've just recently got into 100+ml bottles too, and for the most part they stay in my bag that I carry everywhere unless I'm steeping them.
tl;dr... Keep them in a cool dark place for steeping, then just keep them out of direct sunlight.
Hope this helps!