Newer versions of iOS don't even support syncing notes to Outlook as plain text anymore. iOS notes only sync to iCloud now, and we Windows folks who like accessing our data directly via files are left to fend for ourselves.
I would look at CopyTrans Contacts which has nascent iCloud notes support. I was able to use it to retrieve my notes from iCloud with SOME rich text formatting, albeit slightly mangled in places, and missing attached images, as HTML files on my PC.
Also, it loses the creation and last edited date for the notes (syncing to Outlook Notes preserved the date). If the CopyTrans folks can figure out how to preserve the date, pull down any images and fix the formatting problems, we'll have a decent solution.
For now, it's better than nothing, and your only other option is to e-mail all your notes to yourself (it's okay if you have 100 or less notes and an evening to do it, but for those of us with a few thousand accumulated over the years, not so doable).
Also, if you can program, you might try googling Apple iCloud API, and see if they have an interface where you can pull your notes down from code (who knows)...