Is there any chance of using an outroom or outside cat run to give them a little more space
Unfortunately, Not likely.

But interestingly enough, I read where it can actually be TOO much space that causes the problem. (here in lies the reason for confining to a smaller space). Since the cat has SO much territory to "protect" it needs to spray the areas it feels that it cannot patrol properly. Don't get me wrong, too little space with too many cats would be bad also.

Last evening Sterling sprayed again. This time I had allowed him out of his single room into the room with me and the fosters (I did this during their original confinement, under supervision). So I feel that it most definitely IS the foster kittens that is bugging him the most. Hopefully when I let him back downstairs again (and the fosters are upstairs) things will go back to the dry period.

But if the truth be know, I am seriously thinking of rehoming him. (much to my dismay). But I truly don't see where he has a good chance at being wanted by anyone else. After all, it is not like I can guarrentee that he will not keep spraying.