Any suggestions on where to start with Pressure Increase for running medium sized seat and handlebag on a full suspension rig if going ot be traveling over rocky singletrack with lots of climbs?

A little bit about setup I am on:

- Giant Anthem Alu 29er that has been pushed so rear shock is very firm in the bottom of the travel hard to bottom out.  Currently running195 psi in shock.
- Pushed Fox Fork that is rather plush
- Handlbar Bag will have sleeping bag bivy and some light cloths to sleep in
- Seatbag is stuffed full Revelate pika
- Backpack will hold the rest including some heavy items like 3 liters of water and tools.

Unfortunately time has not been kind so I wont have much time to play with it was going to start with 15 extra psi, might have time to get out on gravel goad and check out but that is about all..

EDIT for info:  Ended up putting another 25psi in rear, and 20 psi in front.  Total additional weight including backpack with 3 Liters of water was about 33 pounds.  I also put another 7 psi in rear tire and 5 psi in front tire.  That setup proved to work well.