That wouldn't work with ADHD. You'd probably sit down and think about all the things you could do with that time without actually doing them while continuously scolding yourself for not doing them, and then get up 5 hours later, 3 of which you felt hungry and 2 of which you felt like going to the toilet.

Yeah, when we are lucky to have a several days long Internet breakage at home (we don't use cellular Internet), all of a sudden things which had been 'not possible' or 'so hard' or 'so tiring' for months or years suddenly become possible or normal or even obvious. We even manage to do things together with family members. Imagine!