Well, low and behold, I MADE IT!

I was flying in F on CX and had them call ahead to get me an escort to get me through immigration/customs. At the same time, they called my bag tags ahead so that they were out right away. The were the first two on the carousel. Ran up to the LINK train, waited 3 mins 25 secs for one. Got to Terminal 1 3 minutes later.

The bottleneck was with AC. I wanted to switch to the 8:40 PM flight, and the desk agents couldn't help me. They told me to pick up a white courtesy phone and call AC directly. I finally got someone on the phone that changed my flight, with fee, of course. She wouldn't get off the phone with me, and then told me that the latest check-in time for lunch was one hour before and it was currently 7:39. So, I rushed her off the phone and ran over to the checkin desk. When I got there, it was 7:41 and they initially denied me checking my bags. After some cajoling and asking for a supervisor, they agreed to accept them but made no guarantees as to whether or not they'd make it.

I got through US customs, boarded the aircraft and was in my own bed last night, safe and sound.