Moving from 1.8 to 1.11 shouldn't require any changes provided that you're running with 0 deprecation warnings on 1.8. The new release scheme means that if you're running on an LTS with no deprecation warnings, then you should be able to upgrade to the next LTS release with no changes (but lots of new deprecation warnings).
Hope that helps.
https://docs.djangoproject.com/es/1.9/internals/release-proc...