Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Inverness to San Juan as you normally would.
Inverness (INV) is the airport you will fly out of if you book a flight from Inverness to San Juan. You should not have trouble finding flights to San Juan from Inverness; the airport handles an average of 0 outbound flights to San Juan per day. You should also have plenty of airline options to choose from since 1 airline has flights from the Inverness airport to San Juan. It is only a 7.9 mi journey to Inverness (INV) from Inverness’s city centre.