Regulation 45 of The Government of Maintained Schools (Wales) Regulations 2005 http://www.legislation.gov.uk/wsi/2005/2914/regulation/45/made states that
The governing body must hold at least one meeting during every school term.
If the meeting is postponed until the Summer term and the governing body does not meet during the Spring term then this does not meet the statutory requirements of the regulations. The meeting would therefore have to go ahead. Could the headteacher prepare their report early? Another member of the senior management team could attend the meeting on behalf of the headteacher to present the report.