As of last week, Facebook implemented a new "Legacy" feature. This feature lets you choose a Legacy Contact who can take over the account if something is to happen to you.

https://uk.lifestyle.yahoo.com/facebook--legacy-contact--can-take-over-if-you-die-135903037.html

They can choose to take over, or simply delete your account, but likely this will be something you'll discuss with them ahead of time. Personally, I've chosen someone with a similar sense of humor who can carry on the laughs. Who will you choose?