I think in much of the uk unless you are seriously short of fuel youve got a good shot ot getting yourself visual with a base of 600 to 800 feet - not suggesting you would want to but when the devil drives.
Your real problems start with bases of less and every where socked in.
With a total panel failure this could be a life saver but then again how many airports with an ils couldnt also provide a sar in an emergency?
Continueing a sar or letting down with this box of tricks when the base is really on the deck should prove interesting mind you.