Relocations don't solve dating problems in most cases. There is a situation where relocations can make a difference. It is a similar situation to the one
@nicksaiz65 is facing right now. A relocation from a smaller town (under 150,000 population) to someplace larger (150,000+) can solve dating problems. The biggest problem in smaller areas is a lack of options. The area where
@nicksaiz65 lives right now is under 150,000 population and
The main reason that I like Nashville for you longer term is that you have a history of living in Tennessee. That can help for social circle introductions at some point in life. In Miami, you're just another transplant with no connections to the area. Even if you stay in Miami for 5-10 years, you're probably not going to get into the good Miami social circles as a transplant to Miami in his late 20s.
You could have social circle options if you stayed in Tennessee based on your past and present in Tennessee.