More than the peak workload, you have to think about the opportunity cost: Any time you spend doing Bunpro and KaniWani reviews, you are not spending on other things. How many hours is it going to take you to learn and review all those N1 items? How many new words could you have learned in that time instead?
Looking at the big picture: What is going to make you fluent in Japanese? Using the language. A lot.
All the SRS in the world isn’t going to get you there, it’s only the stepping stone that enables you to use the language. So the goal should be to get to the point where you can watch shows/read books/listen to audiobooks/… a lot and actually understand things.
What is going to get you there? Core grammar and core vocabulary. N1 grammar is so infrequent that it barely makes a difference in your understanding. The top 2k most frequent words appear all the time, learning those makes a giant difference.
I’d love to continue with a rant on how English → Japanese quizzing (like KaniWani) is also much less useful than one believes when starting out and is probably time better spent elsewhere, but I think I’ll cut that short by borrowing someone elses words 
TL;DR: Any time you spend on something, no matter how little, is time you could be spending on something else. Every time you choose to spend your time on one thing, you’re also choosing not to spend it on something else. An insane goal like N1 (or even just N2) in a year is going to require more than just a lot of time spent studying.
(Sorry for the unsolicited advice, after years of learning Japanese I’ve developed some pretty strong opinions. It’s hard not to jump into these kinds of discussions 
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