Here is the worst case scenario: you are last to board and unusually every overhead around you is full: if all else fails, the crew will help you to place the bags at the end of Club World, which will typically have half a dozen empty overheads there after the bedding has been distributed. But that's unlikely, it's not something you should spend brain power upon. If it is a matter of concern just move down towards row 52 which is usually a quieter area on the A350.