I've done a lot of hiking and camping, running ocean marathons etc in my life. Lived near the sea and inland alike. I would most definitely join a large group to attempt this. I'm still very fit, have a lot of go in me, haven't had the flu in about three decades. ...but then haven't encountered living in snowy and below zero climates. That might be a challenge! As far as those regions @Fernapple mention, my skin colour would surely be good-to-go or fitting-in-with-the-looks or features of those regions. Fitness, Eating right, Resting Right and Stamina is key.
@FrayedBear. Living in South Africa in Africa, camping in reserves etc is challenging enough and enjoyable . I've had close calls too.
but Yip I'll watch that video, those who wish to attempt and record. Now that would be a challenge!

Fun fact. Guessing the length of time it takes to travel depends on how fast you can walk

Wow! I would think that if a person, or a group of people, wanted to attempt this, and could record it on video to live stream parts of the journey each day, they might be able to finance it with sponsors and advertisements (for travel gear, etc.) and write a book about what to expect if others wanted to try it.

I'm thinking there would be some unsafe areas, for sure! Interesting to contemplate. I, for one, will wait for the movie. I'll leave the experience to someone else.

That's 3.09 mph. x 561 days @ 8 hours per day.

That's if you get out of Cape Town alive!