Asking strangers for $400,000 so you can go on a long vacation is not how reality works.
Here are some options that might work in the real world:
People do these sorts of trips these days(without the cost of live streaming from the middle of nowhere) but they mask them behind some sort of money for charity money raising ruse. They also don't try to get all the money up front.
Another option is to pitch the idea of two guys doing a big expedition with no training as a TV show. Google the show "I shouldn't be Alive" for reference.
A third option is to spend several years building an expedition resume on your own dollar, then come up with a sponsorship worthy objective and approach potential sponsors to cover the cost of air flights or maybe donate some gear.