Welcome to Portland - I hope you're enjoying it here :)
You ask a good question about the venue! The one we have used regularly is booked for that night, so we're going to be using a brand new one. We are going to be meeting at 6PM at Mozilla's brand-new Portland office, which is at:
1120 NW Couch St
Make a note of that as the address hasn't get been added to Mozilla's site as far as I can see. I wanted to announce the book title and Leah joining us as soon as possible, so I did that before I had the venue sorted out.
If you're on Twitter, it's worth following @uxbookclubpdx as things sometimes get announced there more quickly.