I wouldnt touch it as the longest "expiry date" I have seen on PG/VG is about 4 years. VG isnt that expensive.
I recently found a full 500ml bottle of PG that expired a year ago. I will only use it in my cigar humidors (I still love my Cubans and don't inhale).
I doubt it would make you sick or taste completely terrible, but again, why chance it?