ChartJs – width scale of chart area and label area

May be following settings will work for you. Set responsive to true and maintainAspectRatio to false in the chart options and set style as like as max-height: 300px (more or less); width: auto; in canvas.

...
var config = {
  type: 'doughnutLabels',
  data: {
    ...
  },
  options: {    
    ...    
    responsive: true, //IMPORTANT        
    maintainAspectRatio: false, //IMPORTANT
    ...
    legend: {
      ...
      position: 'right',
      ...
      labels: {   
        ...  
        fontColor: '#d5d6d6',      
        fontSize: this.isMobileWidth ? 10 : 16,
        ...
      }
    },
    animation: {
      animateScale: true,
      animateRotate: true
    }        
  }
};
...