Argh, I thought I was on to something. I just remembered that displayport can support daisy chaining, so I figured I'd look for a USB-C hub that had displayport in it...no dice. There are plenty of hubs with HDMI and adapters with displayport (only), but nothing with both. Argh.

*edit*

Ok, now I'm really wondering what's up. This Verge article from May describes a USBC hub with minidisplayport in it, but for some reason it only had USB2 not 3. Now the links to that company's website for that device are dead, and their site only lists a USBC hub without any monitor connections at all.

This is strange...