I have a trip in a while that has me ending in LAX on a Mon-Wed. My wife is then flying IAH-LAX-OGG, picking me up in LAX, and we're getting in a couple of days in Maui, then heading back to IAH.

My routing forced my LAX-OGG segment into a B fare and instant upgrades are available. We can purchase W fares for her IAH-LAX-OGG and back. LAX-OGG isn't that long of a flight, and it's on a Wednesday, so ordinarily, we would just get exit rows and hope for the EUAs, but since I'm already on a B fare, we'd be willing to pay for her upgrade to ensure that we both get in F.

Is it possible to buy up the LAX-OGG portion to a B fare and leave the IAH-LAX a W? Or do we have to buy up the entire direction? My wife would rather not pay for the upgrade from IAH-LAX, if we don't have to.

If the buyup to B is cheap enough for just the LAX-OGG segment, we'd probably do that. Otherwise, we'd use 17,500 miles to upgrade her, which should cover the entire direction IAH-LAX-OGG, yes?

Her ticket is available two ways. As a "direct" flight with a stop in LAX or as two separate segments (if I force a stop in LAX). The price is the same either way, and so are the flights. Does the direct flight affect our upgrading options?

Thanks a bunch.