This is a tricky subject.
Premium services are very expensive, and costs are ongoing.
I have devised an elaborate plan which addresses every risk I could imagine, without giving up control of your keys or risking collusion. It took me 6 months of thinking and testing.
However I have decided not to write about this, as publicising inheritance plans exposes Bitcoiners to extortion risk.
I do offer to help anyone set this up, and just a small fee for my time. See mentorship program.