As long as you have the crap tires on all 4 corners, use the reduced grip to balance the car through the rear swaybar. That way, when you have nicer tires, you will know how to control the car when it loses grip, and it will be balanced, mostly. Then you can change the handling as nessasary through tire pressures.
A balanced car with no grip is a blast, by the way. Its like racing in one of the pre-aero GP cars.