"3 kids through Watterson" - okay, so nothing personal, but, if you're a Watterson parent then it's evident your viewpoint is a little myopic on this one. Of the four comprehensive, co-ed schools in Franklin County (and, for that matter, the nine co-ed high schools in the Diocese of Columbus), Watterson draws from the wealthiest parishes and the wealthiest zip codes. It's of no surprise to anyone that those who are sacrificing to send their children to Watterson are doing so largely out of religious reasons (because, obviously, districts like Grandview, UA, Dublin and Olentangy aren't rough places to be... so the difference between BW and their public school counterparts is the faith aspect.) With schools like Ready, Newark and Fisher Cath, and probably to certain extents DeSales and Hartley, though, you have families who are primarily enrolling their children in because those schools are seen as being more functional, safer and conducive to learning in ways superior to the public district (SWCS, Newark, Lancaster; Reynoldsburg and Westerville.)
The Catholic schools are hemorrhaging the Catholic families of this generation. Enrollment, nationwide, is continuing to decline. With regards to Central Ohio, the landscape is actually more dire than it appears. The comprehensive, co-ed schools of Franklin County are buoyed by the voucher system. The risky proposition of moving Bishop Ready outside of Columbus is the fact that such a move would entail an independence from the voucher system. The window to boost enrollment, and create more schools (k-8 or 9-12) closed about 15 years ago. St. Elizabeth Ann Seton, of Pickerington, will always be a PSR parish, despite the fact it had the numbers to justify its own school (as 20-25 kids a class at St. Pius X are in PLSD.) The aforementioned Church of the Resurrection in New Albany will never develop its own grade school, despite the fact its a parish with the wherewithal to do so, because it is flanked by the two largest grade schools in the entire Diocese (St. Paul of Westerville, and St. Matthew of Gahanna). The Diocese has owned the same plot of land near Orange Road in southern Delaware County since about 1998, but hasn't done diddily with it. St. Mary of Delaware can only admit 45-50% of prospective students in a class because it has no literal room to grow, expand and cater to the demand.
I don't think that Ready will necessarily close, but they're not in that great of a situation regardless of whether they would move or not. The Westgate neighborhood is changing toward a demographic that isn't conducive to private school enrollment, as it is largely becoming a neighborhood populated by "DINK" couples, yuppies, the gay community, and generally progressive people (who favor public school options over parochial ones.) Factor in the recently built and surging Cristo Rey (sp?) that is by the downtown library, and Ready is going to see less of the downtown urban student population coming their way. At the same time, moving to Grove City (are we talking inside 270, or outside 270?) would likely be ill-advised. As mentioned already, you lose the voucher safety net with a move. The other issue is a school like Ready, although maybe not Ready in particular, whether people want to admit it or not, are in "sink or swim" mode - they need to be able to diversify and sustain said diversity in their student portfolio: hey, the devout Catholic families are great, but what was once the group that made up the overwhelming majority of Cath. school student population is starting to instead become a plurality. They would need to really concentrate on getting more kids out of SWCS if they moved to Grove City; the problem is, right now, outside of the always-reliable Our Lady of Perpetual Help, Ready is losing in the private school market game in SW Franklin County to Grove City Christian (a school whose ascent in the past 10 years has made it the second-most prominent non-denominational Christian school in Franklin County, after Worthington Christian.) While I'm hesitant to suggest that this currently is of detriment of Ready, with consequent advantage to GCC, Ready is experiencing great periods of waxing and waning in their boys sports (except for football... which is generally the one solid program): soccer and baseball are down, and have been down for a short while now, and basketball is either really good or really bad (very little in between). GCC is also playing in what has become a very formidable and reputable small-school sports conference in the MSL-Cardinal, whereas Ready plays in a five-team conference that they usually find themselves toward the bottom of in several sports a year. Obviously, the CCL >>>> MSL-Cardinal in many ways... except winning and the recognition and pride that comes with consistent winning is going to largely supersede playing in the lion's den of sports and generally doing middle-of-the-pack or worse. The other thing that isn't helping Ready is Seaman's reluctance toward building a damn football field (seriously, being nomads to the extent that Ready football is forced to be frankly is a little... odd.) On Hoover Road, though, you get to play on a very nice football field.
I think Ready can weather the storm, but it's not unreasonable to say that their situation is a little bit tricky compared to the rest of the Franklin County "four."