There still needs to be a better way for folks to get notified about these sessions more than 1 day in advance, but here’s how you can at least make sure you get prompt notification about these:
Go to the Events section by clicking on “Events” under the title for this topic. Then, click on the little pull down over on the far right of that page (next to the “New Topic” button) and change that setting to “Watching.” This should cause you to get a notification as soon as a new topic in Events gets created. The downside is that this might result in you getting notified about User Group meetings nowhere near you.