If you see availability, book first / business class now.

*A has good options to EU with US / UA / LX / LH / TK. PHL-MAD flies 333 with Envoy Suites. UA has flatbeds - not as good as Envoy Suites but close, if you fly on 767 and can get middle isle. LX new C has flatbeds. LH has new C on selected routes.

If you wait until US leaves *A, most likely you'll have to book BA ( bc a lot of people would be competing for US / AA seats which don't have outrageous YQ ), and . . . well, redeeming on BA costs almost as much as paying cash fare.