Right now, I’m leveling up every 7 days. So I can take that and punch it into the progress tab on this site. WKStats has a place where you can adjust the progress to see how fast it takes to get to specific levels. I would highly recommend checking it out.
Although fair warning, they are sunsetting APIv1 keys soon, so I don’t know how long WKStats will be up. I think they’ve been working on a refresh to the website, and I’m assuming that would use the v2 api key. If this means nothing to you, then feel free to disregard it 
At the rate I’m leveling up right now, I’ve actually had zero issues with it and I don’t feel stressed about the amount of reviews I do. Here’s a breakdown of how that goes for me:
- I level up every Sunday at 5pm. First thing I do is do the lessons for all the radicals using the reorder script.
- After that, I do 10 kanji lessons per hour. Sometimes more, sometimes less. The first batch of kanji have a sort of grace period since you’re still waiting on the radicals to unlock your next kanji
- At this pace, I’ve gotten all the radical and kanji lessons done within a few hours.
- For the vocabulary, every hour, I do whatever reviews I have at the time, and then do 5 lessons. This makes it so that at any given time, I’ll only have 10-20 reviews due every hour. This makes it super manageable and I can leave it and let them pile up to be done later, or I can just do them on the hour.
- After a few levels of doing this, things are paced out how I like them. The only thing is that in the morning, I’ll have to work through 60-70 reviews that may have become due over night. But nowadays, nothing comes due during the night because I don’t do lessons after a certain time (usually 9pm)
That’s been working for me, and it’s worked great so far. I’m not sure how I’ll be adjusting it for the fast levels, but I’ll cross that bridge when I come to it. Hope this was a little bit helpful!
p.s. definitely read @jprspereira’s guide. It helped me out immensely