> Moving from 1.8 to 1.11 shouldn't require any changes provided that you're running with 0 deprecation warnings on 1.8.

Yes, this is how it's supposed to be. This agrees with Django's roadmap (see the "I’m the maintainer of a reusable application. Which Django versions should I support?" question at the bottom): https://www.djangoproject.com/weblog/2015/jun/25/roadmap/

However, it depends on the third party apps you're using. I have a Django 1.9 site that uses django-mptt. The site was running warning-clean, but when I attempted to upgrade the site to Django 1.10, it broke because of this issue: https://github.com/django-mptt/django-mptt/issues/469