The drives are encrypted without a boot PIN. If I could exploit a vulnerability in the OS I could get the data. There will probably be a vulnerability discovered, at some point, that will allow access. I'd advised my friend's widow to hold onto the computers for the time being.
Please also advise her to power it on every 2 or 3 months or so (and leave it running for a bit), so that SSDs continue keeping the data, and HDDs don't get "stuck".
Just as long as she can keep it from connecting to the internet.