In the past two weeks, Cheapflights users have found many deals under ₱1,744/day when booking a rental car in Patagonia. The absolute best deal a user found was for ₱1,201/day from Econorent, booked on Jul. 28.
Booking early almost always ensures you have more options of car models to choose from, as well as prices reduced by up to 10% to make it a great deal. Try to book at least 45 days prior to when you need the car rental to close on a rate below the average.
The length of time you can book a rental for is subject to the inventory of the supplier. When renting a vehicle from Patagonia it should be possible to rent a car for a whole month if needed.