Better yet, retain a lawyer for this purpose. The difference being that the lawyer can make determinations this site cannot. For example, you might think that a one week period is sufficient however you'd be better off with a one month period just for safety reasons as you might be stuck on some mountain or locked up with some mob boss for a week and you don't want the dead man's switch to trigger. But what if you're coming home from the mountain climbing trip or the meeting with the mob boss and you get in a car accident and in order to relieve brain swelling, doctors have you in a medically-induced coma for six weeks? Oops...

A lawyer can make such a judgment call without falling back to the binary decision of "has the time elapsed with no check-in?".