realistically EWR and IAD will see the majority of the XLR’s as they will replace current 757 flying and augment existing international routes (if slots available) and new international markets.

the rest of the Airbus bases may see a few if a route requires it for length and or lay flat seats (looking at you Hawaii or South America)

but a 15 hour 3 day already is the norm at least for DC. So a two leg trip vs 6-10 legs for the same pay is usually more desirable.

and the 321 will be flying slower then what currently goes transatlantic. A 756 trip to DUB pays 15:10. Add probably another 30 mins to that for a 321. CDG on a 777 pays 16. So a 321 doing similar lengths would pay much more each trip since it can’t do .84 but only .80 under the best of circumstances.

Work smarter, not harder.