Sills - rear inner & outer rotted at rear & corrosion on subframe

Hi, I wonder if members can quantify the seriousness of the problem. Obviously the extent of the well known problem will define the cost of likely replacement as will the chosen restorer. I am keen to continue as the car (which I have owned since November 2017)  is two owner, otherwise immaculate, as new -  (at least topside) and has every conceivable extra a Dec 2003 3.0 litre could have. Seafrost with biege interior and all garaged like new !  The car has been serviced by Jaguar main dealers ever since its build, currently has 79k on the clock and been serviced every 5k.

Any, all comfort welcomed - I would like to continue to maintain and keep the car for the long term - 10 yrs plus,  there is a lot of sense and experience out there - please share your thoughts.........

Regards

Dominic