Being a small wiki, with few contributors and little articles, wiki
licensing could be switched to a dual license like GFDL-Cc-by-sa.
Cc-by-sa is very similar to the GFDL terms, but license text is not
required.
You would need to contact with all contributors to get their agreement to
publish their previous work under cc-by-sa too. Changing the licensing
informationg would make the future ones. And a strong community consensus
required :)
Be aware that contributions previous to the switching will be GFDL-only so
you couldn't publich it under the second one. This may not apply to trivial
information (e.g. like those ips usually give).
Unrelicensable texts could either:
-Be deleted (the strict way)
-Tag them with a template saying 'some parts of this may not be available
under CC ' (the easier way)
Platonides