Hi all, first time poster here.

First a little background, I fly pretty infrequently (once, at most twice a year) on SQ typically for vacation (.'. on my own budget), from either US or Canada to Singapore. So for this year, I'd like to seek some advise from experienced trans-pacific/trans-atlantic flyers on what you think is the best route for YYZ->SIN. I am planning for the trip to be either during the Xmas period, or the lunar new year period.

What I did last year was take a separate YYZ->JFK non-SQ domestic flight, then SQ25 JFK->FRA->SIN. While it was an overall decent flight (didn't really think that the food out of FRA was good, but I digress), I personally am wondering if that is the most optimal way to travel from YYZ to SIN.

If one tries to book directly from SQ, what the system will suggest is YYZ->LHR->SIN, with the YYZ->LHR on AC. The cons: YYZ->LHR will not be on SQ . This route is also the most expensive. The pros: I can opt to take the A380 for the LHR->SIN leg, given that I've yet to fly on the A380 yet. The total travel time is also the shortest, but I'm not really too fussed about the total travel time. However, the con of flying YYZ->LHR on AC is a huge turnoff for me.

The other route I was contemplating was YYZ->SFO (domestic flight), then SQ1 or S15. The total cost of this route happens to be cheaper, but I'm not sure if it's worth the hassle to go from the east coast to the west, and then fly over the pacific.

Any suggestions?

Thanks in advance!

Edit:
Another alternative would be YYZ->IAH->DME->SIN I guess?

I should also mention that I have been traveling in economy for these long-haul flights mostly. A quick check at my KF account also showed that I can upgrade from economy->business for one of the legs, if that provides any useful information.