If the management can see it clearly, they will choose a specific weekdays(of cause not friday~) that have the least passengers after 2300.Further more, they can always close 1 track direction and not 2. They can always adjust the frequency after 0000, or just extend abit the feeder's last bus.
Or so, they can always have dirrect shuttle buses from CBD to Ang Mio Kio w/o stopping, then passengers going to stations inbetween Bishan <-> CBD get's free ride or something? [That's my opinion].
To me, if I'm commuting between CBD to Woodlands, I would rather take the hard time of letting the team settle these tracks than having to ride the train with fear of breaking down mid-way. If every Singaporeans can be more understanding than complaining etc., I think this maintenance "exercise" can be good for both parties.
Of cause this can't be happening for every replacement, they sure affect the service. Perhaps they can set aside some breaks inbetween the maintenance period. And thereafter, the next maintenance year(major) would be 10-15 years later? Base on the sleeper replacement. And they can do minor inspection every week to maintain, which doesn't requires any shuttle service(1-430am).