I don't have any specific knowledge of their work patterns but would imagine (with only 1 route so far) it's 4-6 2-crew TransAtlantic crossings per month with the odd Stand-by duty thrown in for good measure. I hope they don't have BA's abaility to Force Draft (Draft Assign as it's now) on your days off.
Month in, month out I would guess that pilot turn-over will be quite high. From experience of 2-crew long-haul, I can assure anyone that it is very tiring.