I'd avoid the fridge - either the freezer or a cool dark shelf. In the fridge you can get water vapor condensation which can interact with sugars and airborn mold/bacteria to spoil the juice. (While it is possible that can happen in the freezer, the chances are much lower and the growth rate is nearly zero.)
The DIY guys have similar suggestions to the linked post - glass bottles in the freezer for long-term storage, but bring to room temp (or at least warmer) and mix well before taking some out, then the rest goes back in the glass in the freezer. The rule of thumb there (mostly for unflavored) is 2 years and open as infrequently as possible.
A few months in a dark climate-controlled place should be fine, its pretty much what you do to steep it anyway
