I had the same question a while back and as of now, AT will not grant “partial credit” for your workout. It’s all or nothing, that is, you either completed it successfully and get the full progression level increase or you “failed.” The workaround I had (if you want to know your progression level) is create a custom workout that matches the ride. So create a 90 minute interval at whatever wattage you rode and upload it, and AT will assign it a PL. It’s not perfect, but for now, that’s all you get.