johnydep

As far as I know, the DSC only works when it detects excess steering angle to vehicle motion; which indicates an under-steer or over-steer situation. And a few other things like wheel spin & brake lock-up through sensors on all four axle shafts, a angle sensor on the steering shaft, engine & vehicle speed sensors, gear selection, brake & accelerator pressure.

If the overall height of the tyre is not changed, the sensors for the DSC should still do the job. The tyre change may only cause the DSC to work more or less, depending on traction, overall height of vehicle will be the same.
Changing the height, as in lowering the vehicle, to make the taller rims look better will probably effect the DSC more than changing to bigger rims but keeping the original 28.1"/714mm dia.

In the end having a rim size of 19 inch and a good quality low profile tyre, that still keeps the original Territory size of 28.1"/714mm may only cause a harsher ride.
Unless traction is adversely affected the DSC should never operate in normal conditions.

I suppose there is only one way to find out – someone has to try out the theory.
Any volunteers?