Thank you very much for the help and advice I received through this extension process. Now I received my approval decision, so I want to share my timeline and experience to help more people.
Timeline:
22th December 2016- Application sent.
06th January 2017- Biometric Enrolment Invitation received.
10th January 2017- Biometric enrolled.
24th February 2017- Approval Confirmation received.
27th February 2017- BRP card received.
One week after biometric enrolment, my partner and I got a letter from Home Office basically saying that our case is extremely complicated and they won't be able to make decision within 8 weeks time. I was panic for a while until read some threads talking about this kind of letter. If you received this letter, it's probably because Home Office wants you to know "We are quite busy at the moment, please do not call or write to us if we can't give you a result after 8 weeks". Overall I am quite happy with this timeline considering we had Christmas and New Year holiday from the end of December.
Please feel free to ask any question. I will answer it with my best knowledge (But sorry maybe not very prompt because I am on holiday
![Smile :)](./images/smilies/icon_smile.gif)