I am considering using miles to take a flight from LHR to the USA. It will be an open jaw, probably. LHR-SLC MKE-LHR However, my plans might change after departure. The return might move by a week, and become IND-LHR
I have enough miles to do this in Biz on UA, AA or CO. How will I get on if I try to change my ticket if it was purchased using miles? Is it better to book with AA, CO or UA.
Thanks