What about just adding an if-statement like this:
<cfif size GTE 1>
<cfset orderquery = QueryNew("FIRST_NAME, LAST_NAME,FILE_NUMBER,JOB_TITLE_DESCRIPTION") >
<cfset temp = QueryAddRow(orderquery, size)>
<cfloop index="i" from = "1" to = "#size#">
<cfset temp = QuerySetCell(orderquery, "FIRST_NAME", mydoc.rowset.ROW[i].FIRST_NAME.XmlText, i)>
<cfset temp = QuerySetCell(orderquery, "LAST_NAME", mydoc.rowset.ROW[i].LAST_NAME.XmlText, i)>
<cfset temp = QuerySetCell(orderquery, "FILE_NUMBER", mydoc.rowset.ROW[i].FILE_NUMBER.XmlText, i)>
<cfset temp = QuerySetCell(orderquery, "JOB_TITLE_DESCRIPTION", mydoc.rowset.ROW[i].JOB_TITLE_DESCRIPTION.XmlText, i)>
</cfloop>
</cfif>