low risk low cost approach to yeast "stretching?"

This is probably and easy one, but I've done some searching and can't find a specific answer to this question...

I am brewing the a series of IPAs over the next two months and plan on using the same yeast strain (CA Ale) for all of them.

What is the most efficient, most cost effective, and least risky approach for the yeast use? Is there an easy way that doesn't involve to much transfer to brew up a starter, split that into four amounts in different containers (maybe old bottles), and then use those four sub-batches to create new starters as I need them to brew with?

Is there a better approach?

Based on my time availability and open fermenters I can't count on simply brewing on top of the previous batch's yeast cake.

Thanks for your thoughts.

you can do like you said and just split the yeast into small sterile jars/vials or you can do this