My preference is for spelling to be modernized but words left unchanged with explanations when the meaning has changed,
like this
All the Canterbury Tales: Modern Spelling and Original Words. A Reader-Friendly Edition. where the spelling is modernized (as is generally done with Shakespeare) but otherwise the words are left as is and definitions/explanations are provided.
[PDFs of this version of the tales can also be found here
http://academic.brooklyn.cuny.edu/we...phy/murphy.htm with permission to download for personal or pedagogical use]