Same here, I’ve used yeast that’s been in the fridge for over a year. Online yeast calculators will tell you that the yeast has 0% viability, but start small and you can usually coax it back to life. But best not to let to go that long.
I have no concerns about using a vial that is 6 months old. Just make a starter, maybe 1.010 wort just to get it going, and then step it up to a standard starter. Then again, I pitched a jar of Kveik slurry that was over a year old into last fall’s cider. The Kveik took an extra day, then barked at that cider and tore through it like a boss. Have faith in yeasts’ ability to survive under fridge conditions... that stuff survives in nature through the winter and manages to make it to spring.