Bermuda
Anguilla
That’s two....gimme a sec.....I’m thinking OK
Uh....uh....Mustique.....
OK...I give up
Bermuda's population is 64,268 and Anguila's is 13,600.
The tax-haven aspect is probably critical to the islands' prosperity, and I don't see how you could scale that up enough to help. Just Detroit's population is 706,585.