Some thoughts...

A) See the following February threads as they will give you some ideas:
- Reno Air-Free Companion Travel-to June 15 (note this will only get you as far as Chicago)
- Get a free American Airlines companion ticket!
- Doing the Math on Two-for-One Deals

B) Consider flying out of LAX instead. Fares are usually about 1/2 price to YYZ than from SAN; plus there are plenty of non-stop flights to choose from on Air Canada and United.

C) If flying out of LAX isn't a problem, then go to www.canada3000.com which is a Canadian leisure travel airline. The schedules are pretty slim, but the pricing seems to be the lowest. A couple of friends used them and were happy with the service.

Personally, I would shoot for a non-stop from LAX (on UA or AC) or obtaining the AA Free Companion Pass (by applying for the credit card... I'm certain the free coupon has already been given away).

Good luck!