The Vancouver to BKK flights are doing well for Air Canada, too bad their service is crap (heard first hand from a few people)
They would use an A350, it is alot cheaper to operate than anything they have now. If the interest piques, then more flights would be in order, from LAX or SFO.
The 777 is at the edge of its range, so no go on that, maybe a flight through Japan, I've done that run on Thai before.
I don't believe Thai has anymore A380's, probably not enough interest anyway.
Hopefully through LAX, not SFO. I live 80 miles from SFO, but LAX is easier to get to from Sac, weird I know.