I buy 30ml amber (brown) glass bottles to store mine in; since I make only small quantities, I don't want to have a lot of nicotine "opened" in the fridge -- I may only take out 3ml at a time, so I don't want to have larger bottles that get opened so many times. Plus, small bottles are easier to store -- I keep them in the same box the glass bottles came in, taped shut, so even with the freezer opening from time to time, they won't get any light.
Neither PG nor VG will actually freeze, and nicotine comes in either PG or VG. If you use the kind in VG, be aware that you'll need that nicotine to come to room temp before you try to use any, or you won't be able to draw it up in a syringe, it's too thick and being cold, even thicker.
Andria