Third party described events more often then not seem to have parts of the events missing. If the coach has been unusable for eight months the reasons were not described by the original poster which raises additional questions.
Looking at this as a disinterested party based on the description the owners have been inconvenienced and unless there is a specific rider as part of the insurance coverage or language in the policy the claim will be refused. Vacation or trip interruption will not cover the owner for a trip that has not occurred.