Thank you for your feedback @mandaeanlipwiggle.

I completely understand and I assure you that we will do our best to solve this issue so that you can successfully import the demo.

We’ve recently addressed a very similar issue in another topic:

Modify the sidebar

As the content can’t be imported, our best guess is that there is a limit that prevent to import the demo completely.
Can you confirm you reached out to your hosting company and asked them to increase this limit for you? If you want to do it yourself, we suggest you to add the following snippet via FTP at the .htaccess file:

php_value post_max_size 32M
php_value upload_max_filesize 32M
php_value memory_limit 256M
php_value max_execution_time 300
php_value max_input_time 300
php_value session.gc_maxlifetime 86400

We’re waiting for your feedback.

Best,