The original idea was that Saber would be living in the Emiya household, but without any of her normal, positive energy. On the contrary, she would be depleted and without the will and/or need to live. Moreover, living near Shirou's room, she would have to hear two bunnies going at it nearly every night. I don't remember what involvement Rider would have in all this.
But, now that Archer's going to find her first... I wonder how that will develop.