$60-70k is a very nice salary for Puerto Rico. Not knowing the salary your family enjoys in Florida, it's hard to do a comparison of whether you'll have more after-tax, after-basic-expenses income in PR or Florida. PR certainly has a higher cost of living and your tax liability will probably be higher (please note this is not tax advice) than it was living in FL, but depending on your husband's current salary, the raise may justify the move.
You will be comfortable on $60-70K in Carolina. There is no question about that.