Earlier quoted context omitted.
IMHO, once you've got a db attached, "secure cookies" are a bad idea.
without reference to this project - Perhaps you meant storing all session data is a bad idea versus just an ID? (If so, I'm with you) If not - how would you identify an authenticated user? Or, how would you look up all their relevant session data in the DB?
A db based session, which really wouldn't be that hard to set up with github.com/gorilla/sessions, would just send a randomly generated session id to the client in a cookie, save the data in the db, then read that data back out of the db on the next request.