Any boat can be worked on to enable them to be singlehanded.
There is no real difference between a singlehanded boat and one being run by a couple, except, the boat for the couple needs to be modified so that she can be handled by a 100lb weekling, rather than a 200lb gorilla. (yes I have been looking in the mirror again).
The only problem with these bigger vessels is the docking
, and even that is really only a question of finding and being familiar with an effective berthing technique.
It is well within the capability of most people who consider themselves blue water
, to be able to make these changes. The design of the change is either experience or cheque book time.