It would depend on the Cape Air route and the excess capacity the other Cape Air hulls have and the time availability of pilots and crew. 1,000's of flyers are left all over the globe all the time. If BVI Air can sign the correct treaties you could take your BVI Air ticket to the other carriers. Many airlines like Southwest refuse to sign the proper treaties. Millions continue to naively or arrogantly fly Southwest and the other non compliant airlines. Spend some time in the Jamaica and Cancun airports to watch passengers left high and dry.