The trap we've found in a mid -sized city (~2 mil) is that while there are a lot of people who want turn up, there are FAR fewer who are willing to help out and create content. Sounds like you had that issue with the PBIUG.
Last year we changed from a speaking/workshop event to running the sessions as hacks, where you just bring a laptop and hang out - Now that was nice and low maintenance, but as an organiser you end up just helping people install RStudio over and over again. And then there always seems to be people that show up without a laptop expecting a talk, despite clear instructions to the contrary.
We decided that was again not as much fun as we'd like... so for our first session of this year we're running it as a reading group. We put up a couple of blog posts on web scraping a month ago and we're going to discuss the approach and code in the session, followed by a 'let's try outselves' hack, time permitting. I can let you know how that goes in a few days.
TLDR: With a small population of useRs it's been a struggle to find a sustainable user group meeting format.