Only the first of your two conditions needs to happen for bitcoin to be $100k. If bitcoin reaches an audience of 10% of population (700 to 800 million) by 2021, which is certainly possible, that alone will raise it up to the $100k range. There doesn't need to be anything more than just normal fiat inflation. If there is for some reason a drastic fiat inflation, which I don't see why there would be, that's how we could have bitcoin be worth several hundred thousand dollars in a few years
If ifs and ans were pots and pans
Your arithmetic is simple (if not to say, primitive), so there is little chance the numbers it produces could happen in real life. First, there is no consistency in the Bitcoin camp itself, and now we have two competing Bitcoins (yeah, I know that one of them should be properly called an altcoin). And in just about two months there can be one more Bitcoin (though its fate or even its emergence as such hasn't yet been decided). Apart from that, there is the world of altcoins which are ready to take Bitcoin's throne if it is gonna fail or just show weakness
Well we are talking about the future so everything is "if", unless you can see the future!
My point was it is pretty straightforward to see Bitcoin going to $100k, just needs to continue on its current course for a few years without any catastrophes and it'll hit $100k.
And no, there is not a single altcoin ready to take bitcoin's throne hahaha, that's why they are called altcoins. And who cares about altcoin forks of bitcoin?! Bitcoin cash was created and bitcoin went up by $2000 in the following month! Bitcoin cash didn't even put a scratch in bitcoin.