How low will the dollar go?
Well, in 1914 a $20 bill could be taken to the bank and exchanged for a $20 gold coin. With that $20 gold coin you could purchase a very nice suit. Now a $20 gold coin is worth about $1300 and will buy you a very nice suit.
Since then, the dollar is worth about 4% of what is was in 1914. I expect it to be devalued by about 50% over the next 2-4 years and it may accelerate after that until were are like post WWI Germany or Zimbabwe recently.
You'd have done better if you bought $20 of the S&P 500 and reinvested your dividends.