Sounds like Plan A won't work, and on certain routes even finding 2 CW seats is a toughie (but that's the way the programme works - if BA can tempt a miles punter where otherwise it may not sell the seat its a win - win).

Plan F may well involve 2 of you on the reward flights and two on an ex-EU fare (meeting up as you go thru London if you will). I've got one of those planned and will do another next Summer. Adds the the adventure "meeting" family in T5.

Good luck with the decisions.