In Old English: (10+) Everest; In Modern English: (5) Tree Line
How tough is "The Wanderer"? Well, that kind of depends on whether you want to read it in Old English or modern English. If you want to read it in Old English, it's definitely a 10. If you don't already know Old English, you'll have to spend a few months (or maybe years…) learning it. And even then, all the twisty-turny grammar and lost or ambiguous word meanings makes translating Anglo-Saxon poetry difficult, even for experts.
Decided you don't have time for all that? No worries – there are a lot of good translations. Many verse translations, like the one we're using (found here), preserve some of the difficult grammatical constructions and compound nouns of the original Old English, while translating the poem for you. Score!