I work remotely as an academic editor and writer, and have done so for 5 years. The transition from full-time employment to part-time remote work was interesting. I tended to work all the time without leaving much room for self care. What we do in our jobs, we tend to do when our boundaries are relaxed.
I often have large blocks of free time. My productivity suffers (I have personal writing and creative projects) when I don't organize myself well. After years of fine tuning, I have a system that works well for me.
I discovered and addressed three issues:
I am effective for only about 5 hours a day. Anything more and the quality and efficiency of my work suffers; moreover, my physical and mental well-being declines. Accordingly, I work 2.5 hours (with a 5 min break) then take a large chunk of time to play; then I work 2.5 more hours (with a 5 minute break). I find that during play time, I often have creative insights.
Unless I schedule in fitness, fun, and socializing I am likely to waste my time with unhealthy (Netflix) activity. In your case, you might spend your whole time writing 4 articles! That is quite a hefty commitment and your sabbatical time likely should include time for pondering life's meaning and reading the stack of books that is piling up.
Get up when the sun rises and go to bed soon after it sets. I've done all combinations of working all night, playing all night and everything in between. I feel the best when I follow the sun. When I was in Orkney the nights were 4.5 hours long and it was enough sleep for me though I usually sleep 7-8 hours a night. I don't understand it, but there it is.
Although there are many options the productivity tool I found most effective is bullet journaling. It is simple and quick and there's no software involved (although you could buy some if you want to). I create a daily plan bar https://bulletjournal.com/blogs/bulletjournalist/daily-plan-bar
and I also have a weekly plan
And I never beat myself up for varying from the plan if something more enjoyable arises.
Have a great 6 months.