Custom single page based on which custom page template is selected

Yes it is possible using get_template_part();

Assuming that you use a standard single.php:

<?php
/*
 * Template name: template-blog-left
 *
 */

get_header(); ?>

<div id="left-sidebar">
  <!-- Here your left sidebar -->
</div>

<div id="content">
  <?php 
        //This function will look for single.php file in your theme folder
        get_template_part( 'single' );
   ?>
</div>

<?php get_footer(); ?>