Anyone know what the likelihood of getting an upgrade is in this situation? My wife and I purchased tickets in Z class on United from SFO to BKK via NRT. I have gold status on UA. I'm considering paying the co-pay and miles to upgrade from Business to First on the flights over and back.

My question: Right now the webpage says no confirmed upgrades are available, and that we are only eligible for the waitlist. I'm wondering when the waitlist generally clears and what the likelihood of clearing on the flight is? Our flights are on the 744 departing SFO on June 11 and returning from BKK on June 23.

Also - If I pay the copay now and then only the segment from NRT to BKK clears, do they prorate the co-pay, or is it the full amount regardless of how many segments are cleared? I read the blurb on UA's webpage but wasn't exactly sure.

Thanks for any insights.