Old, no-traffic post, but has a 50-DR backlink. What to do?

I've got a very old post on my blog that gets no traffic now.

I've tried improving/updating it, nothing works. It's dead.

Normally, I'd just delete.

But it's got a nice high-DR backlink pointing to it.

What would you do?

I'm thinking I could just keep it and let it sit.

I could 301 redirect it to the closest-related post possible.

I could delete and 301 redirect to homepage. I've never done that before and don't know if that's even a good, sound SEO strategy.

Any advice would be a big help. Thanks.