I guess, train will be a better
option, coz:
MRT: Usually will increase
frequency, with more trains, kind of like "special
peak";
Bus: Affected by road closure,
congestions etc.
Any views on this?

Trains are also likely to be packed (more so especially after the
event)
Last year I walked to somewhere near City Hall MRT, then there's a
bus that would bring me to Little India Stn, from there take 48.
Takes a bit more time but are there anymore bus options?
National Stadium was the best! Walk to near KFC then 16 would
come there.. It's also not very packed 