So after spending quite a few nights up trying to secure LHR - SIN in F / CW before Xmas 2015 I gave up. Honestly, hats off to you people on here who have managed to secure these seats ^

We are planning to honeymoon in Asia over Xmas and NY 2015 and I have secured 2x one way seats to KUL in F using the 2-4-1 on 23rd Dec. The plan is to go to a few places in Asia and then try and open jaw it back from SIN or HKG in F, and wrap both under the 2-4-1, but quite frankly I don't fancy my chances. Therefore I'm looking at some other options:

(1) Not worry about not getting BA flights back and travelling Cathay in F using 2x Avios one ways (i.e. burning through a normal one way F redemption charge for 2 people) [don't worry I'll still have well over 1m leftover ]

If I do this I might want to fly KUL or SIN to HKG and then have 2/3 days in HKG before flying back to LHR in F on Cathay. Is there a way to book this using Avios as one trip or would I need to book separate legs; i.e. KUL / SIN to HKG then HKG - LHR separately?

- If I did the above and later this year some availability opened up on BA flights (e.g. from SIN or HKG) could I call the Exec Club and grab two F seats (and combine with my 2-4-1 redemption made one way to KUL) and then cancel my Cathay redemption (HKG - LHR).

If so, so I do all of this through the BA Exec Club? - And any idea what the cancellation charge would be? Also if CW seats opened up I presume they would charge less Avios for what would effect become a mixed class return fare?

(2) Cross my fingers and not book any return flights yes and hope that some availability comes up. We are looking to fly back 13/14/15/16 Jan 2016 so have some flexibility. Is it worth taking this risk or better to book some full Avios seats as in (1) [in your opinions!]

Some general questions (sorry if you think they are stupid!)

- Presumably all Avios redemptions will need to be made through the BA website from my Exec Club account. It's probable that I'll be making them on Cathay and Air Malaysia
- Presumably all are cancellable and cancellation can be done from Manage my booking or would I need to call the BA Exec Club (or Cathay / Air Malaysia)

Thanks so much for any help!!! It's the one part of the Honeymoon my fiancé has tasked me with to get sorted and I want to make sure I use my Avios wisely and maximise the travel experience for her.