Mythopoet
Auror
Now I want to read a high fantasy novel with a world based on Tuscaloosa, Alabama.
Lol...
Well, there's a fantasy book set in a small rural county of Tennessee called The Hum and the Shiver. Might be close enough.
Personally, I like to know in general the size of my world so I have some sense of how much room I have to work with. But I don't like to place precise dimensions or do detailed maps because I find that limits my creativity more than it helps. I do a lot of "big picture" worldbuilding for the whole world but only do very detailed worldbuilding for the setting of my current WIP. I like having a sense of a very large world out there even if it's not all in my current story.
But then I'm the sort of writer who develops one large, intricate world and writes all their stories in it rather than building whole new worlds for each work. Having a large world gives me a lot of leeway for different types of settings and different kinds of stories, but also having them all contribute to a greater whole.