I started poking around in fares on EF a bit more.
LH has a good one. But surprisingly it doesn't show up on GF without forcing it.
YYZ-FRA with a late departure, ample time to enjoy the SS. I'd probably go on the 26th.
FRA-SIN and SIN-FRA on LH
FRA-YYZ on AC. Then I just need to figure out how to go west from there.
And the fare difference between not-upgradeable and upgradeable isn't too drastic, such that I'd be tempted to book D for the return since SIN-FRA is F6 (FRA-SIN is F0).
Need to figure out the logistics here, but this works best at the moment. AQM on all segments, some AQD, Signature Suite, good schedule, and a chance for LH F.