@aral Congrats!
I've taken a full backup and stopped using my Google account like 6 months ago but didn't delete it.

In case of Facebook, I kept my account unused for 4 long years before I finally deleted it.

I think I'll let at least a whole year pass for my Google account too to really make sure that I don't need it for anything. I've deactivated everything except Gmail already. Letting go of all the purchased Android apps was a bit painful though.