Anoother option might be to reroute from DFW to another international gateway from which the OP could catch a same day connection to a BA flight with premium economy available. This would add another stop to the itinerary and transferring terminals at ORD, BOS, or JFK might not be particularly pleasant. It also would mean flying farther in AA domestic coach and having a shorter and therefore less restful nonstop TATL flight. However, it sounds like the OP's arrivial into DFW will be sufficiently late to make such a same day rerouting difficult if not impossible.