Bolts, the guys here could be a little clearer. I'm a newby, but I'll try to give a clear answer.
Four wheel drive will not necessarily help on ice and nor will ABS because the Landy is quite heavy and its inertia will slide it across a junction with all 4 wheels locked up if you're going too fast. It would be best to stay in a lower gear, say 3rd instead of fourth, then change down to 2nd on the approach to the roundabout or junction. This means that all the wheels are still turning and the front ones are still steering, but the engine is braking the vehicle down without you touching the brakes; this is much safer. This is the Engine Braking that someone mentioned and it's a technique you should consider whenever you suspect that there's ice ahead.
HTH