I am no expert, this is just what has happened in my experience. This may not be safe or smart, just my experience. I had a tackle box full of
juice that somehow got left in my garage for about a year. Most of the juices in the tackle box were at least 6 months old when they got left in the garage in the first place. After the at least a year of sitting out there, I came across them and began to question if they would be any good, even safe to vape. I took a chance, because I was low on funds and newer juice. Every single one of those juices tasted much better than I remembered them originally tasting, they satisfied my nic cravings just as well as my newer juice, and I didn't get sick or nauseous off of any of them. It may not have been smart, but in my case they were just fine.
As far as refrigeration, I read somewhere here on ECF recently to NEVER put juice in the refrigerator. Don't know if that's the truth or not. In my garage that box of juice went through extreme heat and extreme cold in a year's time and they only seemed to get better. I've never put mine in the fridge because I have three nosy kids that would try to drink it or add it to milk for flavoring!