"At the end of my break I look forward to work in developing solutions that involve distributed systems or work in setup, management, and monitoring of complex distributed systems (dev OPS role)."

I think a far better way of getting into a new field of software engineering (like distributed systems) would be to apply for a job in that field, let them know you've been studying it in your spare time but are an experienced software dev with ~15 years under your belt. I think that would be a pretty good offer for an employer (at least a good one). At worst you may have to take a small pay cut but that should certainly be a lot less money lost than if you took a 6 months sabbatical.

If you can afford a 6 months sabbatical then I say take it, but try spending the whole 6 months without touching a computer, or at least not coding. It will help you grow as a person and make you a better software engineer when you come back to it after the 6 months.