My plan was to have the availability groups split across all the 3 nodes at each site. Each server will act as the primary for a portion of the availability groups. I currently have a similar setup with my 2012 HA AG's. I am going to spec each server so it is capable of running all of the groups if required.

The reporting replica is not required locally. What I was hoping for was to have a reporting replica; running asynchronously at Site B. making the report generation that much smoother at each location.

As far as tempDB sizes go on the readable secondaries; I've already created some scripts that will clean up the temporary statistics daily. I have been running the setup for nearly a year with no adverse problems standing out as of yet.

I"m going to draw up something quick to give you a better idea of what I have envisioned; I'll post it up when it's complete.