Even schools and colleges have cricket grounds but you can't just host international matches there. Nassau Cricket Stadium, which hosted the USA's leg was a temporary setup and the day T-20 WC ended, they dismantled the structure. Having said that, the Olympics should change the scenario and one could hope for at least 2-3 good permanent stadiums, not sure if they have any dedicated ones if we leave Central Broward Park.
I am not sure whether the USACA guys will like that suggestion or not. If there is a permanent structure, then these guys will not get a lot of opportunities to do corruption. USACA has been the most corrupt national cricket body for the last 2 decades or so. They got suspended from the ICC one or two times exactly for this reason. But then the ICC just loves USA. They believe that USA is going to be the next gold mine for them. Central Broward Park is a good option. But don't forget the fact that out of the 4 matches scheduled there during the T20 World Cup, three were washed out.