When is your trip and what is your originating airport? Presently, Indonesia still requires COVID test (specifically, PCR) no more than 48 hours prior to departure - but the requirement may change.
If 3) unable to continue SIN-DPS due to positive test is your main concern, then 2) is the most viable alternative because 1) will be terribly uncomfortable. The SQ lounge gets extremely busy in the hours leading to midnight.