Obviously it will restrict the post-death reach of your blog, but the most foolproof solution would be to print our your articles and store them somewhere safe.

Obviously it will restrict the post-death reach of your blog, but the most foolproof solution would be to print our your articles and store them somewhere safe. The average person can read a 100-year old book just fine. Digital storage changes too quickly. The average person can't really access information stored on floppy disks, and those were ~30 years ago.