real answer - have generational wealth, attach the documents to your trust. This should last either until your nation’s currency collapses or the trust value does.
Trust documents are usually held privately, and not publicly recorded (as their entire point is to shield this estate planning and asset holding from the public). If you put it in someone's will, upon their death the will would be recorded and it would persist as long as the jurisdiction does maintaining the will on file.
For high reliability, I think I would suggest engraving it into a low reactivity nonvaluable metal, perhaps titanium sheet would be a good choice. Couple that with a backup on printed archival paper using carbon toner or an art-grade ink or dye. Between the two of them they will probably resist damage for 100 years or so.
Brass or bronze would also be a decent option, but you'd have to make the text larger for it to be readable with corrosion. Perhaps braille would be an interesting choice there.
And ceramics are a great choice - clay tablets, when fired, can last millenia.
I think between the three of a metal sheet, clay tablet, and paper book, one of the three is almost certain to survive a century.
40 years - print and bind the google doc in 20 years, store it with their stuff when they leave the house.
60 years - publish the book buy a bunch of copies and distribute
100 years - it needs to be a very good book