I hope this is the right place to ask this question.

I had booked an AC round trip departing evening of July 1 with the outbound path SFO-YVR-DEL. I just received an e-mail from AC changing just the outbound flight to SFO-YYZ-DEL departing over 12 hours earlier and taking 6 hours longer. I can deal with the additional flight time, but the earlier departure and arrival would require both my partner and I to take an entire extra day off work and book a hotel for the extra night in Delhi, which is expensive and inconvenient.

My question is: what exactly am I entitled to if I want to change my flight? Ideally, I'd like to rebook to an itinerary that leaves in the evening, even if it takes slightly longer to arrive, but it doesn't look like AC has any evening departures on July 1 anymore that don't have us arriving nearly a full day later. I can see an itinerary with departure time similar to my old one on a *A partner (Turkish Airlines) -- would I be able to request to be switched to that flight instead? If I have to accept the worse itinerary, is there any chance of at least getting upgraded if I call in and complain/ask nicely? Can I expect AC to pay for the additional hotel night in Delhi?

I read the international tariff and APPR linked earlier in this thread, but they seem to state that so long as my _arrival_ isn't delayed, I'm basically entitled to very little besides a refund, but flight prices have gone up so much since I booked that a refund is essentially >$1k down the drain.

If it matters, the stated reason for the change in the e-mail is that "part of your itinerary has changed due to unexpected business or operational constraints on our planned flight schedule".

Thanks in advance for your help!