The first few weeks I did absolutely nothing but workout, read books, play video games, or just lay out in a hammock. But as soon as the stress started wearing off, I started feeling the itch to make things again. Because I didn't have anywhere to share what I was making, I ended up organizing a local meetup for Rust, which ended up getting me my current job doing shit that I love. Though when I accepted the offer I made my start date a few weeks out just to round my time off up to three months off. That was the happiest time of my life. I fully intend to take at least that much time off if I ever leave this job too. (Though I might even see if I can swing a three month long vacation/sabbatical without leaving once my project is released.)
My only advice: do it.