I'm writing up a guide for a basic, easy to setup, baselayer bitcoin inheritance plan. There will be a few tradeoffs upon your death, but it should work and your bitcoin won't be lost and will actually reach your heirs.
I call it a baselayer because it should be just your backup plan to avoid catastrophic loss upon death, while you figure out an even better plan. Or the community/technology in general improves.
Fwiw I'm an experienced New York executor and probate attorney.