We are doing the same thing. We have no real agenda or plan so we can stay or go any time we want. But, we want to make sure to cover the US in two years, so we don't stay too long.
We have a general idea of what we want and a general idea of what we don't want. Honestly, sometimes in less than ten minutes we can make a pretty accurate assessment. For example, we pulled into Alamogordo, NM today. It was almost rush hour. There is no amount of money you could pay me to live here. So, another town off our list and it took 10 minutes.
Sometimes, we fall in love with a place. One such place is Hunting Island and the area around Beaufort, SC. We returned to spend more time three times in six weeks. We didn't want to leave and plan on returning next winter.
Spend some time wandering. The more you know what you don't want, the easier it will be to find what you do want. We still have the entire west coast (Oregon!) to check out and don't want to make a decision before seeing them all...