I take back my previous advice. The following canons do not seem as absolute as you claim, and it is already too late to follow them perfectly, so more consultation with a priest us needed.
Can. 1176 §1. Deceased members of the Christian faithful must be given ecclesiastical funerals according to the norm of law.
§2. Ecclesiastical funerals, by which the Church seeks spiritual support for the deceased, honors their bodies, and at the same time brings the solace of hope to the living, must be celebrated according to the norm of the liturgical laws.
§3. The Church earnestly recommends that the pious custom of burying the bodies of the deceased be observed; nevertheless, the Church does not prohibit cremation unless it was chosen for reasons contrary to Christian doctrine.
Can. 1180 §1. If a parish has its own cemetery, the deceased members of the faithful must be buried in it unless the deceased or those competent to take care of the burial of the deceased have chosen another cemetery legitimately.§2. Everyone, however, is permitted to choose the cemetery of burial unless prohibited by law.