If it were me, I wouldn't do anything until things are finalized. You are NOT a family anymore, your W has made sure of that. All kids hope their parents get back together. I talked at length with a child counselor in my first D, and she said often times kids will wish for that subconsciously even when the mom and dad are both re-married. My XW1 and I only spend time together at things like school plays or sport events.
By doing things as a "fake family", you're only going to give them false hopes, especially D6 as D4 may be a bit too young to understand completely. W just wants to have this happy pretend life where the kids are OK and she doesn't have to feel badly.
