daily WaniKani reviews
This is good at minimum, though I’d recommend doing them 3 times a day to maximize the SRS benefits, as others have said here already.
daily Bunpro reviews
I haven’t used bunpro but it seems like a good system, daily seems like a good pace for bunpro.
2 weekly 1H-sessions studying Mina No Nihongo (I intend to do all the exercises)
This sounds good, I’m not sure exactly what the pace of Minna no nihongo is, but since it’s entirely in Japanese, it may take some more work to get through it. You may want to increase this a bit, but 2 hours a week is still decent, especially if you’re using bunpro as well to help retain what you’re learning.
frequent watch of movies and series in Japanese (I’d say at least one anime episode every other day, and most certainly one full-length movie per week)
Other people are criticizing this, but I think it’s a good thing to do. It’s always a good idea to start practicing listening very early. It takes some time for your ear to adjust to the sounds of japanese. No matter how much vocab or grammar you know, you won’t be able to understand what you’re listening to without practice actually listening to stuff (at least from my experience). Until you know more grammar and vocab, you won’t be learning a ton from immersing like this, but you will be training your ear, which is a good thing.
2 weekly half hour-sessions studying ‘Remembering The Kanji’
I personally don’t think you need to do this, but you mentioned wanting to be able to write, so I think RTK will be good for that. However, writing kanji isn’t really used much nowadays, especially if you’re not living in Japan (even those living in Japan report not having to really write much). An hour a week isn’t a huge time commitment for it though, so if writing is something you really want to do, then go for it.
1 one-hour talking session every two weeks with a native Japanese teacher
As others said, as long as money and time isn’t an issue, you might want to increase this once you have some grammar and vocab under your belt. You might not benefit from increased practice right now, but once you start learning more, it’ll really be helpful to have more regular practice. If you’re not able to increase it, you might want to practice your Japanese either in the Japanese-only section of this forum, on Hinative, LangCorrect, or Hellotalk.
occasional flashcards sessions with Quizlet to review sentences and vocab from WaniKani and Mina No Nihongo (like 5-minute sessions squeezed here and there)
I personally think Anki would be a better program to use than Quizlet. It’s SRS like wanikani and bunpro. I’m sure there are Minna no Nihongo decks on Anki. It’s not extremely user-friendly, but it’s not difficult to use if you aren’t worrying about advanced customization.
I was thinking trying the JLPT N5 in December 2020, is it a realistic short-term goal?
I think you could definitely reach N5 level within a year. You may even be able to reach N4 level. I assume by the time you finish both Minna no nihongo books, you’ll be at about an N4 level, so I guess it depends on if you can get through them both in a year.
Or do you think I miss something?
Once you finish the first textbook and reach about level 20 in wanikani, I recommend beginning to read. There are a ton of beginner-friendly resources you can use. I personally use NHK Easier, Hukumusume, and Tadoku readers. There are more resources in the thread Starting to read Japanese content. With reading, like listening, it takes practice before it gets easier, no matter what level you’re at, so once you’re able to have a basic grasp of beginner grammar and vocab, I think it’s a good idea to start reading.
Edit: Also, you will want to start learning vocab from another source. WK doesn’t teach kana-only vocab, and it doesn’t teach a lot of common words that use kanji. I recommend Tori for this, they have a mode where you can organize vocab you learn in order of wanikani level, so you only learn vocab using kanji you know.