I have seen "single" probates and they were tight. I think there is even more pressure on those individuals to REPRESENT. I know of an Alpha who pledged and whose probate was solo, I think his line name was something like "Lone Ranger" - very appropriate.
I have a friend who told me there was only one SGRho on campus and that ONE person was a workhorse doing more than anyone could ever expect, in turn she was truely repected for her contributions to the chapter by EVERYONE greeks and non-greeks alike.
I think its commendable