If it ever comes to that...
after 7-10 years, the US$ will have little value. A bank run like that can only be relieved by uncontrolled debasement of the currency. As it is, with 5% inflation, the currency loses half its value in about 14 years. With 15% inflation, it loses half after about 5 years. With 50% inflation (which is true in some countries today), it will be essentially worthless in 5 years.
I know, my government bonds will be worthless too if that happens, but my mortgage debt will be wiped out [g].