...it needs 4000 chapters? It's got more chapters than most stories have pages, damn. I'd probably read like 100 chapters before giving up because at a chapter a day it's gonna take me almost 11 years to read it all.
Ok me being unfunny aside I'm assuming you mean 4k word chapters.
It depends, is the short answer. How much time is a little time? An hour? I could read 4000 words in an hour. That's only 67 words a minute. Half an hour? 134 words a minute, I could maybe pull it off. However it mostly depends on the person. Some reason fast, some read slow. How much could I read without burning out? Depends on the story quality. I can read books like Japanese Destroyer Captain or LOTR back to back without any burnout because I love those books, but I can get burnt out with books I don't really care for, like Guerilla by Mel Odom.
I hope I answered the question properly.