Booking early almost always ensures you have more options of car models to choose from, as well as prices reduced by up to 36% to make it a great deal. Try to book at least 90 days prior to when you need the car hire to close on a rate below the average.
Typically, how long you can hire a car for depends on the inventory of the supplier. For Tobago however, it is certainly possible to rent a car for an entire month.