If only one leg gets upgraded
Rookie here. Flying DEL - ORD - CLE. I have an upgrade option using 25K United miles for Polaris Business class. It is very likely the ORD - CLE will get upgraded (45-minute flight). If the DEL - ORD (international segment) doesn't get upgraded to Polaris class - United will refund my miles, right? Even if the last segment (ORD - CLE) gets upgraded - which i dont care about.