First & foremost, any scheduling more than 30 days out is purely notional. Whether that flight will operate, be performed by what aircraft, and on what frequencies & schedules is something which BA itself does not know.

Second, if indeed it comes to pass that you are stuck in CW, you are entitled to EC 261/2004 reimbursement (not compensation) of 75% of the base fare, which would mean 75% of the avios + 75% of any fees (but, not taxes). Wait on that until you return from your trip and file a claim. You will receive pushback from BA, but it ought to be a fairly simple affair before CEDR.