I would highly advise against it. The FDA came out in 2011 I believe, and stated that doses over 40mg a day can cause fatal heart arrhythmias. They had to lower the max daily dose from 60-80mg down to 40mg. While SSRI's are pretty safe in terms of OD, at least with the outcome being death, Celexa is the most toxic SSRI in overdose. Sure, people have taken quite a bit and survived, but I wouldn't want to test it out. In any case, as someone who takes Prozac, I can imagine taking a lot would be highly unpleasant, if not deadly, in Celexa's case.
As Kittycat pointed out, Serotonin Syndrome would not be something you'd want to experience, as well as seizures, heart issues, etc.