Thanks all for the advice.
I'm uncertain how to proceed. I plan to keep someone on staff for a few months (at least until my AC annual agreement runs out) because we want to make every reasonable effort to get records transferred and patients established with a new doctor, including possibly refilling some prescriptions when people have real problems finding a new doctor. Around here there are very few primary physicians who are accepting medicare/medicaid patients, and all of the new doctors who have come to town get employed by the hospital clinics -- and they mostly don't stay very long before they move on,
Keeping PDF's on a regular Windows machine (and closing down AC completely) might be an option -- but I have never found PDF's from other doctors' practices when they transfer to us to be very useful. Very hard and time consuming to pick out nuggets of important information from those endless, repetitive files.