I've done T-30 between Canada & US. I had no expectations but the agent was willing to try at the ticketing/check-in desk. They were able to sell me the ticket no problem, but then it clicked over to boarding and was under control of the boarding gate so they actually couldn't check me in. They had to call down to the boarding gate, who were able to get me checked in, and then they could print the boarding pass. I had no real expectation and was pleasantly surprised. It was the last AA flight for the night and I would've been on another carrier.