Just make sure that they’re at least somewhat logical. For example, I highly doubt Cathay Pacific would be willing to start A350 service to Hong Kong from a regional airport in Idaho.
ISP-CLT (American Mainline)
ISP-SJU (Frontier or Southwest) (Added on Frontier, starts in April!)
ISP-DCA (American Eagle)
ISP-DFW/DAL (American Eagle or Southwest)
To be honest, I could drive just over an hour west to JFK/LGA and have all those routes, but I love the convince of ISP!