I had not considered the effect of asymetric braking and would not expect to have to use that in this case.
It does bring up another factor , however, that of the aircraft, not only wanting to weathervane into the wind, but the 'heeling' affect that the crosswind produces increasing the frictional drag of the downwind main gear.
I think, that, once again though, this affect would be minimized by the appropriate amount of upwind spoiler deflection, 'more equally 'evening the loads on the main gear, and lessening drag prior to rotation.
I think the only way you could conclusively prove anything is to try , in a simulator using varying degrees (and zero) spoiler deflection and noting the effect on ground roll.