Today the Official Roll of the Baronetage shows the baronetcy Lees of Longdendale as being EXTINCT.
It seems that the 3rd Baronet died on 21 December 2018 (probate granted 3 June 2020) - it would be good to find a death notice but it seems most unlikely there would be two persons of the same name
He was the son of Sir William Hereward Lees, 2nd Baronet (1904-1976) and (m 1930) Dorothy Gertrude LAUDER (d 1996). He m 1986 Joanna Olive CRANE. No issue