I would appreciate your advice on my predicament:
We are returning from Sydney in February. We were originally booked VS to travel PVG to LHR in Upper on Wednesday 26 February. Of course, VS then cancelled, and we agreed to take the BA flight for the same route on the same day.
Based on this, we booked CX SYD to PVG in Premium Economy on Monday 24 February (11.05 / 22.00). A snip at £620 per person. Our plan was to spend two nights (and one day) in Shanghai, prior to catching the BA flight on the Wednesday.
However, BA have now cancelled the Wed 26 Feb flight, and rebooked us on the Tuesday 25 Feb flight, departing 10.55. (BA now only fly the route on Tuesday, Friday and Sunday).
We have two concerns:
a. If there is any delay on the CX flights on 24 Feb, we may miss the BA flight on 25 Feb.
b. BA have cancelled several PVG - LHR flights - and we don't fancy being stuck in Shanghai.
We looked at asking BA to change us to HKG - LHR. However, this would increase the cost of our CX flight from Sydney from £620 pp to £1,020 pp (plus a change fee). We don't want to take the risk of "skiplagging" our CX flight. If we cancel our CX flights, we lose £275 per person.

- Realistically, what can we ask BA to do?