Since the question of church planting has struck a nerve, I think it's fair to ask where Unitarian Universalists should prioritize new church starts, if other factors are equal. (But this implies a corporate interest in church planting; yet I live in hope.)
Consider the 577 micropolitan areas in the United States, "as defined by the United States Office of Management and Budget, are urban areas in the United States based around a core city or town with a population of 10,000 to 49,999." Of course, some do have Unitarian Universalist congregations, but the conventional wisdom from the defunct extension office (so I've heard from a reliable source) is that these small towns didn't have a core of already-UUs and that the distribution of Unitarian Universalists -- then about 1 in a 1,000; always made me think of the presence of uranium ore -- meant there couldn't be enough Unitarian Universalists.
But faithful people are made not collected. And micropolitan areas have, in many cases, an attractive way of life. But asking people to leave one area to go -- say, 50 miles -- to a distinct metro area for church is as good as saying "tough to be you."
First step: to know what micropolian area has no church, which of these are growing, and if are any clustered. I'd examine south Georgia, for one.