Ambassador, British Airways; FlyerTalk Posting Legend
Join Date: Apr 2012
Location: Leeds, UK
Programs: BA GGL/CCR, GfL, HH Diamond
Posts: 43,255
Absolutely near zero chance you will be rebooked on to QR if it’s just a time change rather than a cancellation.
For a schedule change you can move up to -2/+2 days (from memory) and you just need any space in the cabin, no need for reward availability. I did have a look at 27 February and unfortunately only one flight has first and there is no space as it’s currently showing F0 A0.