This is a habit I feel like I absolutely have to shed. Luckily, a lot of the impetus to do that will go away when I ditch FB, which I'm going to do as soon as I get my new personal website/blog set up.
I understand why you want a replacement for updating friends and family, but that's a really effortful barrier you're placing in front of deleting Facebook. For this reason you will find it way harder. And it's already harder than you think.
Take any and all barriers away from ditching FB. They are your mind tricking you into staying.
But again, your point is valid. Probably I need to set a "drop dead" date and tell myself "if this new site isn't up by Jan 31 (or whatever), then I'm killing FB anyway".