Thanks for the details, dsgtc0408.
Since getting a BP prior to arrival at SIN is questionable, the prudent thing to do imo is to reserve a room at the transit hotel. Arrival at SIN is at 12:45am, too late for transit desk.
Question - I can stay airside all this time, right? Arrival, hotel, departure without having to go through customs/immigration/security/passport? (i.e "They are all departure lounges, not arrival" comment vs. "Departure and arrival at SIN are co-mingled")