Just my $1/50 worth.
We've had water bottles, both new and refilled in our van for about 2 1/2 years now. This is not so much by design as forgetfullness.

We keep a few in the "footlocker" BOB, some just loose for daily use.

What you have to understand is that we'll see 3 months at a time where the ambient temp never gets above 15-20 degrees.

Of course some of the bottles thaw due to the heater running, others not because they're packed to deep.

I cannot detect ANY differency in taste. Now Mrs. Bear, who has an EXTREEMLY sensitive taster ocassionally notes a different taste, but nothing that could not be tolerated.

BTW, all the refills come straight from our well with no "treatment" of any kind.

-gb