NOT the National Collection.

       By a LONG way; just a daft thought.   ;¬)   BUT I now have three versions.  The local, wild, one, in 2-3 shades, this wee yellow one; and now this one "Digitalis X valinii Berry Canary" which tells me, on its label that  "It will withstand a few degrees of frost but may well require protection in colder winters &/or northern locations."
       Time will tell.