The way things are going you won't need to convert to USD and won't want to. In a dollar collapse situation you would likely see retail accept crypto as payment directly assuming there is a grid and assuming there are functioning crypto networks.
Crypto is useless as a medium of exchange. It primarily functions as a GFT HYIP game. Transaction times, costs and huge price swings makes it a no-go. Could you imagine If a loaf of bread cost 10 cents Monday, 2 dollars Tuesday then 50 cents wed and 1.45 Friday. Or imagine selling a house and you get paid in bitcoin but a week later you can't buy a home anymore because the BTC volume dropped 40% in a week.
what if big banks get together and give their support for gold (they're loaded enough with all those cash, jewel, asset,...), and make it some sort of hush-hush quasi gold standard (instead of chasing after those crappy cryptos). or intrinsic value has no bearing practical meaning?