Welcome to FT [MENTION=849454]TruffleHunter[/MENTION]
I guess you have been booked in the R fare bucket. However, I am surprised with the schedule change that should be relevant as normally an available seat in the cabin is all that is needed.
There are several options, even in R. Also, is LGW an option for you?
See here from Expert Flyer:
Results from https://www.ExpertFlyer.com
Code:
Flight Availability Search
Departing DOH on 26/01/19 12:00 AM for LON, Flying QR on booking class J C D I R , Exclude Codeshares, Point of Sale: UK
Frequency
Flight Stops Depart Arrive Aircraft Reliability
QR 9 0 DOH LHR 388 Daily J9 C9 D9 I9 R0
26/01/19 1:30 AM 26/01/19 6:20 AM 55% / 27m
QR 329 0 DOH LGW 788 Sa J9 C9 D9 I9 R9
26/01/19 1:55 AM 26/01/19 6:25 AM 49% / 20m
QR 3 0 DOH LHR 388 Daily J9 C9 D9 I9 R0
26/01/19 7:35 AM 26/01/19 12:25 PM 42% / 21m
QR 327 0 DOH LGW 788 M,T,W,Th,F,Sa J9 C9 D9 I9 R4
26/01/19 8:05 AM 26/01/19 12:35 PM 40% / 28m
QR 7 0 DOH LHR 77W Daily J9 C9 D9 I9 R0
26/01/19 8:30 AM 26/01/19 1:10 PM 84% / 17m
QR 1 0 DOH LHR 359 Daily J9 C9 D9 I9 R4
26/01/19 1:00 PM 26/01/19 5:30 PM 63% / 22m
QR 331 0 DOH LGW 788 M,Sa J9 C9 D9 I9 R9
26/01/19 2:30 PM 26/01/19 7:00 PM 82% / 9m
QR 15 0 DOH LHR 351 Daily J9 C9 D9 I9 R3
26/01/19 3:55 PM 26/01/19 8:25 PM 70% / 18m
QR 5 0 DOH LHR 77W Daily J9 C9 D9 I9 R9
26/01/19 5:05 PM 26/01/19 10:00 PM 96% / 15m