According some souces putting it in the freezer should take you at least a year past the exp date that is on the bottle. The date on the bottle will more than likely be a year date of purchase, unless things have changed recently. So you should be able to get two years of life out of a bottle. Here is a link about what is supposed to be the longest life nicotine on the market, however I prefer Nicotine River Nicotine out of the 4 or 5 that I have tried. It is the only one I will buy and I prefer it in VG it is much smoother than PG based nic IMHO
https://www.nudenicotine.com/product/nude-armor-100mgml-nicotine-base-extended-shelf-life/
And here is a link to NR