No, my WE SEL Viognier is only 13 months old. My 18-month rule is for reds. I have only done those 2 whites, but my intention was to ferment them in the summer and start consuming them the following spring (as the weather warms up). My hope is that each batch lasts over 2 summers, but my Viognier is already more than half gone!
I'm trying to keep my hands off of the Viognier until Christmas/New Years, still have 24 bottles, we drank two and the rest were given away with the note "don't open until Christmas" attached to the back of the bottle.
We've been hitting the Pinot Grigio from a juice bucket this spring, already down to 22 bottles and dropping fast. Plus my wife likes it better than the Viognier, which is a more acquired taste IMHO.