You are implicitly addressing several questions.

Where

As so often the documentation is dispersed over several semi redundant pages.

Markup in the Monastery demonstrates the double DWIM nature of code blocks, ie inline without download link (without mentioning wrapping)

Why

Since the intention as stated is to mark ...

"code and data (which can be cut and pasted direct from your editor)"

... and a download link is missing, you can't allow automatic wrapping!

Automated wrapping means you'd get plus signs breaking the code when copying.

How

Personally I hate those cases with overly long lines happening and I think the solution is trivial:

Feature request: Inline code over 80 characters should be treated like multi line, ie get an additional download link and be wrapped!

Reasoning: >95% of the cases so far where careless posters, I'd rather prefer to apologize to the remaining <5% and hear their justification, why they don't want a download link.