Hi Ned,
Not sure about your specific situation. I hit the half century mark here recently and am already planning for a car free future/retirement. Where I currently live it ain't gonna happen. So we are looking at a relocation to a better suited area. Whether we move into the nearby town or pull up stakes and move some where like Boston is still under discussion.
I think it has been proven that you can live car free just about anywhere if you are creative and have the time. Obviously some places are going to work better than others, and everyone's ideal place is going to be different depending on their needs. My preference is a smallish town that has everything in a compact area with access to Amtrak.
You have several advantages in that you are single which gives you a flexibility that married with children don't have. Use it to your advantage and don't be afraid to move outside the box.
Aaron