General Discussion

Tesla shares are only around 25% of Melon's total. (13% of $840 billion or about $109 billion.)
Of course, his net worth includes $44 billion for Twitter, when it was worth about 20% of that. So, there's one inflation point.
SpaceX is a different matter. It's market cap is over $400 billion & he owns 42%. So, $168 billion.
So, we're at $322 billion, out of around $420 billion.
If those tank there is still potentially $100 billion left over. Not exactly GoFundMe time.
Of course, I can't attest to how fragile the other $100 billion is.
If Tesla & SX tank, it could take other investments with it.