Planning to attempt to snag a couple of seats in CW from SYD to MAN for 23rd SEPT 2024 circa 1am tonight(T-355).. will I have to book just SYD to LHR and then amend the booking to add the LHR-MAN connection as the LHR flight departs 24th SEPT 2024 which will still be T-356 when i book? And will they waive the change fee??