Another question on said itin. The wife, mistakenly, booked the one stop to DXB instead of the non-stop from JFK. This first sector is a Flex Plus fare in Business. We can't select seats on this flight-- seats are requested and pending for over a week. I was wondering if it was possible to upgrade (subject to available space, of course) just one segment (JFK-MXP) with miles (since its significantly cheaper) or does one have to upgrade the entire way to DXB? Does EK allow flying two separate cabins on the same flight (number).