Originally Posted by
Kacee
Note that YYZ-NYC is an absolutely awful route for delays and cancels, with EWR being worst but JFK/LGA not that much better. I would definitely recommend an overnight in New York on the outbound.
Yup, exactly. Doing an overnight is de-risking the travel a fair bit. Nothing is for certain though and in an extreme situation OP will still be faced with being on two tickets so that's where travel insurance comes in.
One could try to go via a travel agent (or try OTA) to piece together the YYZ-/EWR/JFK in Eco and then connect to SQ EWR/JFK-SIN in PEY and still get a reasonable fare when on one ticket, but I don't know if OP has access to a good one, plus this usually makes sense for Biz / First type fares where a TA may still be interested to assist, but for Eco / PEY maybe not so much.