No, Thomas and me decided that going to Samui doesn't really make sense any more, since we will have to leave to Bangkok on Thursday. That would be more time on the move then being on Samui.
So our idea is to go from Hat Yai to BKK directly by bus/train. Chartree invites us to make a stop-over at his home in Surat.
We will now check out the hotel and look for a taxi to Hat Yai and from there bus to Surat.