Just an FYI...we recently brewed a Kolsch, using yeast that was harvested over 5 moths ago. Yes, I was a little concerned as we normally re-use the yeast much quicker than that.
Upon stealing a one ounce sample, and doing my "Sniff 'n Taste" test, it is doing great! And the beer will be very good indeed.
So no worries if your harvested yeast is in storage for a few months! It will be just fine.