I am going to cancel a long haul dream trip for the family of 4, made using 2 old style vouchers. Unlikely to to make such a long/expensive in terms of charges, trip with them in future.

​​​​​​As such intend to get a cash/avios/voucher refund so I'm not committing all the cash and avios to being spent on a trip completed by Sept 23.

Assume the vouchers will come back including the extensions to dates already provided by BA?

One voucher would therefore expire before summer 23.
Could I extend that voucher by booking a cheap reward flight, and cancelling for a BWC voucher?

Would I then be able to combine that BWC voucher, and the amex voucher with validity until after summer 23, in order to make a booking for all four people on a shorter trip than our original one?

I suppose what I'm asking is would I be better using both vouchers on a short booking that I cancel, (therefore having to use both together in the future) for a BWC voucher. OR just do this with one to keep the option of using both 2-4-1 vouchers separately at some point?