Hello!
Intuitively, I would say: Fly the constant heading computed for zero wind condition all the time (assuming that the cross winds are of equal strength and change direction in the middle). The first half of your journey, you will drift in one direction, the second half, the drift will be reversed and you will arrive exactly at your destination. Your velocity vector will point in the direction of your destination all the way and you will not lose effective speed compensating for the crosswind.
max