How old is too old for frozen grapes?

[jsiddall]

I am considering trying winemaking from grapes and am looking at some frozen grape buckets from October 2012. Is over 2 years old too old if they were properly stored (kept frozen)?

 

[jpsmithny]

I made a Pinot Noir in January 2014 from frozen grapes harvested
in October 2012.

The wine was very good.

That doesn't answer your question however as it would now be a little over 2 years old.

Have you asked the supplier if they have ever done this and what was the outcome?