I've not tested this myself as I don't really run endurance races so I can't give you exact percentages but I'm told that adding camber can have a positive effect on tyre degradation. It will have a negative effect on peak lap times but you might be able to strike a balance.
Other things that will affect tyre wear are:-
Toe settings - The closer to 0.0 you are the less you will scrub the tyres
Weight - The less the car weighs the less damage it will do to the tyres
Downforce - Similar to the effects of weight, less downforce, less force acting on the tyre
LSD settings - Too open and it will shred the inside tyre, too locked and it will kill the outside tyre
Driving style - The more smooth you are with brake, throttle and steering inputs the longer the tyres will last
Drivetrain - FFs and 4WDs are hard on their tyres, MRs and FRs are generally less severe as long as the tyres and levels of power are balanced.
Its all a balancing act really, each method has its pros and cons. If we take downforce for instance, lowering it will reduce high speed tyre wear but it might increase the likelihood of over rotation and wheelspin which will have a negative effect on tyre wear. There is no real fixed solution and reducing tyre wear by 50% is unlikely if not impossible, you'd be lucky to see 10-15% unless the car is badly set up and really hard on its tyres.