I have been using conan almost exclusively (other than lagers and a few other test batches) for the better part of the last 9 months. I have had a couple fresh pitches.... but, basically, I have brewed off of 2 different Heady Topper Starters and a pack of Giga Yeast. I can get at it more easily than you, but what I generally do is I brew a batch of my "house ale/lawnmower beer" which is a low hopped blonde ale, 1.040 gravity. I harvest 6 half-pint jars of yeast from this batch and store in fridge under fermented beers. I will use 4-5 for whatever I want to brew over the next month or two (making a starter with each). With one or two of the jars I will brew another batch of blonde ale..... harvest 6 half-pint jars and repeat. I find the blonde ale is a perfect yeast-generating beer, plus lots of visitors love it because it is light, clean, easy drinking.
This might not be a method that will make it last forever..... but you could take it through a year pretty easy (with good process) I bet. I brew about 15-25 batches off of one pitch. Could carry it out longer, but I know I have relatively easy access to it, so I simply don't take it past that.