I always thought it was a 10 metre run!?! Either way, you know the customer is going to balk at the threshold strips. Maybe just try for matching silicone joints in the doorways, although that may not be possible, due to laying out.. The other option is that you could explain the potential problems, of tiling right through, and just go with what they decide. I've done it a few times, and so far, been lucky. 
