After researching this, I was able to fix it by going into /etc/php/7.0/apache2/php.ini and doing the following:
setting max_execution_time to 3600
setting max_input_time to 3600
Then, navigate to /var/www/html/nextcloud (at least in my case) and issue the following command:
sudo -u www-data php occ maintenance:repair
Once completed, I was able to restart the updater in the web interface to complete my upgrade. I’m all set! Thanks for everything 