MSTA moved their old HUB event to Heritage USA in Marble Falls. Not sure what drove the choice or what all is there vicinity of the park.
I don't know, doesn't feel right about them operating during remodeling...Well, isn't that something. From the photos. Heritage USA is the exact same building as the old Hub. Investigation is needed to see if they can accommodate our group. Thanks, Krampus.
This campground looks promising: Tyler Bend Campground - Buffalo National River (U.S. National Park Service)
Another NPS site but this offers group camping sites and showers!
Plus it looks like there are several cheaper motels nearby.