Concrete "post footings" for concrete patio floor?
As long as the total contact area of the footings in consideration of the load bearing capacity of your soil exceeds the total dead &amp; live load of the patio, then it won't settle into the ground.

As long as the footings are below the frost line, they themselves will not frost heave.

However - if the slab is still in contact with the ground, then it will still be susceptible to frost heave. The entire contact area of the slab with the ground - except the footings - will be above the frost line and can get damaged.