Draw the vectors for gravity and cornering force from the C.G. and add them up. If the vector falls outside the tires, the car will roll. Inside, it won't.
That's a static example. In real life you could probably do something stupid that would change the dynamics. That's probably more likely with something stiffly sprung. I've rolled go-karts, so I know what can happen when you do something stupid in an unsprung vehicle.
Stiffening the suspension alone doesn't make the car that much more likely to roll, except possibly for the reduced camber compensation, which would ordinarily slightly increase the track.