Your best chance is probably to spend most of your 100 days praying
From noob to GM in 100 days

I say go for it - you never know if you never try! And if you're in a position to do nothing but chess, make the best of it! ;) Although only 4 hrs sleep per day will probably slow down your progress...

Maybe 20 hours a day is too much I agree, but at least 12 a day is needed to reach GM status in 100 days right?
Wrong. How much time you study does not matter. Gaining enough ELO points to earn GM status (2500 ELO) is not possible in 100 days even if you have a winning streak in 100 days.
Obvious troll is obvious.