Hi OpticalSanity:
I don't think you will find a USB-C to MagSafe 2 cable.
HyperJuicer released a battery bank with MagSafe cable at some point, and was sued by Apple. So they changed the MagSafe cable to a kit to allow you to use an old magsafe power supply to make your own cables. https://www.hypershop.com/products/hyperjuice-external-battery-pack-for-macbook
Here is a video of how to do it. https://www.youtube.com/watch?v=HUDeKmetMnY
Hope this gives you some ideas.
Kim