Citizenship certificate is listed as acceptable document:So my friend spoke with his lawyer, who said that she does not recommend traveling outside of Canada with out a PR card or Passport. The lawyer said there is a good chance one can be denied entry with the certificate. At the end of the day, it will come down to the border officer and more times than not, they will refuse entry to the person.
The lawyer also said there is no way to immediate the certification, unless its a family emergency. But i guess there is no harm in asking them anyway after the Oath.
Hope this bit helps.
https://www.cbsa-asfc.gc.ca/travel-voyage/td-dv-eng.html