I'd say you can't do it only because it's sorta on a schedule. The moment you are on a schedule you are pushing and you wear yourself out. Back a few years ago I started out on a 2 week tour, with no base mileage; had been a cyclist 20 years earlier, but virtually no cycling since; had serious knee and ankle and heart problems. In the first 4 days I did one 40-40-80-90, with a full load. But I wasn't trying to do it, I was just cycling as much as felt good and not pushing it. Terrain, wind, weather, good bike, were also on my side. The next two weeks were mostly 80 plus days, and the terrain got worse and worse. But I was just lucky to have all the time I needed, and to very nearly have each day be a little harder than the next, because the governor was me, not some external thing that might have broken me somewhere along the way.

You don't have to train to get to a good level of performance, you have to train to get ahead of where your body says you should be and to start there on day one.