Well I just got my nic, PG & VG out of the freezer and tomorrow I intend to mix another 120 ml batch of 25 mg/ml nic, ~ 70/30 PG/VG. I made the last batch (of same properties) on June 20 according to the label I put on that bottle. I put the last amount from the 'batch bottle' in to my 'filler bottle', bringing the level up close to the 30 mls of that bottle. I'll get at least a few weeks from it, so I won't be needing to fill it soon.
Original source: https://www.e-cigarette-forum.com/threads/another-batch-otw.968691/