Hi everyone, I have a single Avios reward booking LHR-IAD along with a £127 paid seat. I no longer need to fly this leg, but in order to avoid losing £127, I'm wondering if I could change both the date and destination of the booking (to PIT) and keep the seat assignment (PIT is old CW also, albeit 787 instead of A380). I see this in the paid seating T&Cs, but unclear if "move to a different flight" covers re-routing or just date/time changes:

• On British Airways marketed and operated flights, if, in accordance with your ticket type, you choose to move to a different flight, you will be entitled to choose an equivalent seat on your new flight. If an equivalent seat is not available, any sums previously paid for seating will be forfeited and will not be refunded. Alternatively, you may choose a more expensive seat and pay the difference in price.

Also unsure about the re-routing rules for Avios reward bookings in general. I'd paid £495 + 52K avios for LHR-IAD, but the closest pricing option for LHR-PIT is £425 + 50K Avios.

Thanks in advance!