I have not flown on a one way ticket in over ten years, so I am not up to date on it. I am driving up with family for a cruise soon to SEA, but afterwords I am flying SEA-SFO on a one way ticket. I am lucky that the 24 hour point for my flight I am in Vancouver BC in an attempt to upgrade to first.

My question is after all that babble is: Can one call in upgrade or OLCI on a one way ticket, or is my guaranteed "SSSSSSSSSSSSSSSSSS" ticket enough I must physically be at the counter prevent any chance to upgrade?