I think this fact will happen in this year. After Trump 's inauguration , Bitcoin price is rising up higher and it's quite closer to 1,000$ price. it seems the world economy is ready for new crisis when USD is down badly with Trump's decision and it has effected to bitcoin price immediately.
what you are saying is highly speculative. and i have been hearing it for many years about USD value dropping and failing economy of US, and i am not saying it is never going to happen but i have never seen any valid argument and it has not yet happened.
and besides bitcoin price goes up and is better to go up with adoption not just because somewhere in the world economy is shit and more people want out with new investments. that just makes price more volatile.
I guess the slow down in USD against other fiats will be more than enough rather than expecting big collapse of dollars to have boom for bitcoin appreciations. It is already happening as China conquering the number one place as biggest economy of the world.
Trump's new policies are supporting alternate investments indirectly still he will not let down his own currency to fall down. So, we can expect intermediate impacts due to Trump government.