Situation on Whatsapp needing help..unable to get any so far on web

Gurus,

I need urgent help and clarification.

I went through many articles on whatsapp FAQ and rest of the WWW but couldn't find an answer addressing my question.

I was using a Singapore sim card and my whatsapp was registered against that number too. This was on an android phone.

I moved to Malaysia lately and started using Malaysia sim card in the same android phone but my whatsapp was still registered under Singapore number. I understand whatsapp supports this.

Issue starts here: I am moving to a new android phone, from Note 3 to S6Edge, Can i retain my Singapore number as registered number on whatsapp? Because I will put my Malaysia sim to new phone, and If i try to use Singapore number as registered number, it will expect me to verify it with the code sent to me on the Singapore number
Note: My Singapore sim card is no more active. Will I need to re-verify anything? Will backup from old phone and restore to the new phone get my whatsapp up and running on the same Singapore number as registered in whatsapp?

Your urgent clarification and guidance is highly appreciated. What should I do, what are the possibilities and limitations? and whats the best way forward for me?

Thanks
-emm